The Nineteenth Byte

AdmBorkBork

4:01 PM

Yes, it can do multi-dimensional arrays

Unless you mean something else

caird coinheringaahing

@user202729 congrats on Fanatic badge! (a little late but ¯\_(ツ)_/¯)

user202729

Yes I meant array.

caird coinheringaahing

CMC: Double a number using only ASCII characters. In addition, it has to be input-safe i.e. no matter how many inputs it's given it returns the correct answer for the first input (to prevent answers such as + in Jelly)

DJMcMayhem

@cairdcoinheringaahing I'm not sure what you mean. Extra inputs are ignored?

Should the extra inputs be printed or not?

Either (({}){}) or (({}){}<>) depending on whether or not to print extra inputs

Downgoat

@cairdcoinheringaahing (*:2) cheddar

caird coinheringaahing

4:11 PM

@DJMcMayhem Extra inputs ignored

J. Sallé

@Mr.Xcoder APL, 12 bytes {∧/⍵∊1,2×⍳4}. 1 for truthy, 0 for falsy.

DJMcMayhem

@cairdcoinheringaahing But should they be printed? (In languages that print all input by default)

Cause in brain flak, ignoring input means printing it

J. Sallé

@cairdcoinheringaahing I think this is literally impossible in APL rofl

AdmBorkBork

@cairdcoinheringaahing PowerShell, $args[0][0]*2 (so long as you're given numbers as input and not strings or something)

Marcus Andrews

4:24 PM

Shorter way to do this in Ruby?

puts gets.to_i%4>0?"Ok":"A"*10+"!!!"

if input is divisible by 4 print AAAAAAAAAA!!! otherwise just Ok

caird coinheringaahing

@DJMcMayhem You may do what you want with the extra inputs

Riker

@MarcusAndrews should be able to remove the >0, ik ruby too well tho

are non-zero values truthy?

Marcus Andrews

I did, but it didn't seem to work for whatever reason

Riker

and/or can you use truthy values in comparisons?

hm ok

Marcus Andrews

4:40 PM

how about, you are given a line of digits from 1-9 in any order

but one of the digits is replaced with ?

output that missing digit

input 73?492851 output 6

caird coinheringaahing

@MarcusAndrews Can you replace puts with p?

Marcus Andrews

@cairdcoinheringaahing unfortunately no, but i found a shorter perl anyhow that worked

since you can get an int with <>

AdmBorkBork

@MarcusAndrews PowerShell, 30 bytes

Mr. Xcoder

@MarcusAndrews Just curious, what is this all for?

Marcus Andrews

learning codegolfing in various languages mainly, using problems from codingame

Mr. Xcoder

4:44 PM

Ah ok

The thing is that functions are usually shorter and they’re accepted on PPCG; if you want to compete well here, you might want to try to use those too sometimes

Marcus Andrews

in python I have it down to print(45-sum(map(int,input().replace("?",""))))

is there a quicker way to ditch the ? or skip over it when adding ints from it?

Mr. Xcoder

@MarcusAndrews You can do print(45-sum(map(int,input().replace(*"?0")))) for -1 byte (Python 3 only)

Neil

we've had a a question for this already

Marcus Andrews

probably some shorter ruby exists though

Neil

I think the accepted algorithm is 9-int(input().replace("?",""))%9

Mr. Xcoder

4:55 PM

Note that you can create inline code blocks with backticks. `<code>`

@MarcusAndrews Much shorter, 38 bytes print([*{*"123456789"}-{*input()}][0])

J. Sallé

@MarcusAndrews APL, 12 bytes: {45-+/⍵~'?'}

Marcus Andrews

@Mr.Xcoder How about print(*({*'123456789'}-set(input()))) ?

Mr. Xcoder

@MarcusAndrews Better yet: print(*{*'123456789'}-{*input()}) (33 bytes)

Marcus Andrews

wow

impressive haha

Mr. Xcoder

It would be so much longer in Python 2 xD

caird coinheringaahing

5:05 PM

If we can output with surrounding brackets, lambda a:{*"123456789"}-{*a}

Mr. Xcoder

Nope, full program required

caird coinheringaahing

ಠ_ಠ Why?

Mr. Xcoder

Because they actually submit this code somewhere I think

HyperNeutrino

golf.shinh.org/p.rb?Knight+Travel+Speed

all of the answers are under 100 bytes and then there's just this one that's 552 bytes lol

caird coinheringaahing

@HyperNeutrino Almost all are under 50 :P

HyperNeutrino

5:07 PM

yes :P

Mr. Xcoder

And rolf is a good golfer in general... strange

Oh no rofl actually solves the problem. The others are abusing the test cases.

That makes complete sense

caird coinheringaahing

@Mr.Xcoder How do you know?

Mr. Xcoder

I am pretty sure on my judgement, that's all :D

HyperNeutrino

darn I probably should've added all the test cases in existence

Mr. Xcoder

Oh it's yours

caird coinheringaahing

5:09 PM

Jelly is weird

HyperNeutrino

just add all 4096 test cases

@Mr.Xcoder yeah :P

Mr. Xcoder

Do you solve too or just post challenges?

HyperNeutrino

@cairdcoinheringaahing how is that weird

@Mr.Xcoder well I have so far posted 1 challenge and solved 0

caird coinheringaahing

@HyperNeutrino It makes sense to me, but the mathematical notation abuse is weird

Marcus Andrews

hmm

HyperNeutrino

5:10 PM

@cairdcoinheringaahing ah ok :P

Mr. Xcoder

I posted one flawed challenge (test cases) and a "good" one, but solved some more

Marcus Andrews

What about this? Finding the max element of a grid that has 4 strictly-lower neighbors, if none exists, output -666

e.g.
3 3
1 2 2
1 3 1
2 2 1

output 3

my current attempt

R,C=map(int,input().split())
g=[list(map(int,input().split())) for i in ' '*R]
s=-666
for r in range(1,R-1):
 for c in range(1,C-1):
  if all(g[r+i][c+j] < g[r][c] for i,j in [(0,1),(0,-1),(1,0),(-1,0)]):s=max(s,g[r][c])
print(s)

HyperNeutrino

wrapping or not?

Marcus Andrews

no wrapping

HyperNeutrino

ok

you have spaces that can be removed

Marcus Andrews

5:13 PM

values on edges/corners don't count either since they lack 4 neighbors

Mr. Xcoder

You can remove those spaces. Ninja'd

Marcus Andrews

the values can range from -100 to 100

so I don't believe I can remove them

Mr. Xcoder

Oh boy you can

HyperNeutrino

you have at least 6 extra spaces

Marcus Andrews

R,C=map(int,input().split())
g=[list(map(int,input().split()))for i in' '*R]
s=-666
for r in range(1,R-1):
 for c in range(1,C-1):
  if all(g[r+i][c+j]<g[r][c]for i,j in[(0,1),(0,-1),(1,0),(-1,0)]):s=max(s,g[r][c])
print(s)

sorry I thought you meant in the grid itself

Mr. Xcoder

5:15 PM

@MarcusAndrews Also list(....) is equivalent to [*...]

Marcus Andrews

ah right

forgot that

Mr. Xcoder

I am finally prepared to solve Pyth Practice 2 yay :D

HyperNeutrino

-1 byte by doing if all(g[r+i][c+j]<g[r][c]>g[r-i][c-j]for i,j in[(0,1),(1,0)]):s=max(s,g[r][c])

caird coinheringaahing

@Mr.Xcoder I might try that in Jelly (no posting) :P

Mr. Xcoder

@cairdcoinheringaahing Sure how about solving all those in JHT rn?

caird coinheringaahing

5:19 PM

@Mr.Xcoder Given me 10 minutes or so to finish revision, then sure

HyperNeutrino

R,C=map(int,input().split())
g=[[*map(int,input().split())]for i in' '*R]
s=-666
for r in range(1,R-1):
 for c in range(1,C-1):
  if all(g[r+i][c+j]<g[r][c]>g[r-i][c-j]for i,j in[(0,1),(1,0)]):s=max(s,g[r][c])
print(s)

ooh we should ask owner to add jelly to anagolf

Mr. Xcoder

@HyperNeutrino Yes but how shall we contact shinh?

HyperNeutrino

good question ¯\_(ツ)_/¯

J. Sallé

@Mr.Xcoder

Contact: shinichiro.hamaji _at_ gmail.com . If you found some bugs or you have some requests (fix problem you submitted, add language XXX, and etc.), please email me.

Mr. Xcoder

Oh facedesk right

Erik the Outgolfer

5:33 PM

@J.Sallé I contacted him recently and still no reply

J. Sallé

@EriktheOutgolfer I didn't even know that site existed until a few minutes ago, I just assumed there was some contact information somewhere in there and looked for it :p

Leaky Nun

0

A: Determinant of an Integer Matrix

Jelly, 16 bytes LŒ!ðŒcIṠP;ị"Pð€S Try it online!

I'll give a cookie to whomever that can figure out how my code works, and more importantly, why my code works

AdmBorkBork

I'm going to go with "magic" and "magic." Do I get a cookie? ;-)

J. Sallé

@LeakyNun How: Magic. Why: Dennis.

Leaky Nun

0

A: Determinant of an Integer Matrix

Jelly, 15 bytes LŒ!ðŒcIṠ;ị"Pð€S Try it online!

I outgolfed Dennis now

J. Sallé

5:42 PM

Nice

Mr. Xcoder

@LeakyNun You have my upvote :-)

HyperNeutrino

5:52 PM

So LŒ! or equivalently JŒ! gets all permutations of the indices I think

and then ðŒcIṠ;ị"Pð is applied to each of these permutation and summed

Conor O'Brien

6:14 PM

another system definition facility

MD XF

6:52 PM

Is this a valid C quine?

Or are there rules against compiler flags, even if I add them to the byte count?

Pavel

@MDXF flags allowed, yes they add to byte count. However, the -D flag specifically is not allowed for quines.

Leaky Nun

7

A: Determinant of an Integer Matrix

Jelly, 15 bytes LŒ!ðŒcIṠ;ị"Pð€S Try it online! How it works LŒ!ðŒcIṠ;ị"Pð€S input L length Œ! all_permutations ð ð€ for each permutation: Œc take all unordered pairs I calculate the difference between ...

added explanation

I got 7 upvotes before adding any explanation lol

MD XF

@Pavel :(

I'm just rather disappointed that this is still proving ungolfable, despite countless hours of thinking about it

Pavel

@MDXF -Da=main(){puts("a");} and then your code is just a. It's for good reason.

MD XF

That's true.

Mr. Xcoder

7:17 PM

@HyperNeutrino You haven't been to the Enlist chat for so long that you cannot even be pinged there lol :D

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

SANDBOX NOTE I'm serious. This is no less interesting of a challenge than 99 Bottles, or Hello World, or any other simple kolmogorov-complexity challenge. Return the n-th prime code-golf kolmogorov-complexity Write a function that, given a number n, returns the n-th prime. Inspiration. You...

Newly Featured Questions

161

Q: Is this number a prime?

Believe it or not, we do not yet have a code golf challenge for a simple primality test. While it may not be the most interesting challenge, particularly for "usual" languages, it can be nontrivial in many languages. Rosetta code features lists by language of idiomatic approaches to primality te...

4

caird coinheringaahing

@H.PWiz Wow your Hexagony answer to ^ is impressive!

H.PWiz

I had a nearly identical 32 byte one a couple of weeks ago. And just came back with a fresh mind. :)

eaglgenes101

I want to air my idea for a new language

Its native form is a bunch of arithmetic code tables, and the language automatically and repeatedly does lookups using its current table, stopping once it is told to

A stack is available for computation if needed, and tables can be switched and pished extremely concisely

*pushed

Basically, it is a tring complete compression format disguised as a golfing language

*turing

AdmBorkBork

8:00 PM

lol, golfed a byte off my answer for 2spooky4me ... over two years after originally posting it.

thanks @MDXF

Marcus Andrews

Anyone here know perl?

Not sure why I can't do this simple thing:
x=<>
print x

nvm, derp

mınxomaτ

8:20 PM

TIL you can search issues sorted by reactions over all GitHub repos. E.g.: github.com/…

Fatalize

^ 404

mınxomaτ

Not really

Oh wait, now I get it, too ...

Erik the Outgolfer

huh no

mınxomaτ

Very weird indeed. Anyway, the search query is is:open is:issue sort:reactions-heart-desc

Fatalize

Time bomb 404

mınxomaτ

8:25 PM

It has some 45 million results, so it's probably overloaded right now.

DJMcMayhem

Don't you just love it when you go through old code of yours and you find a bunch of garbage placeholder strings that you threw in there for testing and then forgot to remove?

property var text: parent.valueList[index] !== undefined ? parent.valueList[index] : "blah blah blah"

mınxomaτ

I once left 'Blah' as a bullet point in the slides for an investor pitch.

Fatalize

@mınxomaτ Read your notifications REEEEEEEEE

Erik the Outgolfer

@Fatalize huh

what is REEEEEEEEE

Fatalize

A dank cry of anger

mınxomaτ

8:29 PM

@Fatalize I wouldn't have to do that if the damn notification would appear in my damn feed, instead of who starred what and stuff.

DJMcMayhem

@mınxomaτ I should just do a whole folder recursive search for anything matching foo|bar|spam|blah|quux

Fatalize

@EriktheOutgolfer knowyourmeme.com/memes/reeeeeee

Marcus Andrews

@mınxomaτ I audibly gasped reading that lmao

what ended up happening?

mınxomaτ

They didn't see it. It was drowned in buzzwords.

Erik the Outgolfer

lucky you

mınxomaτ

8:31 PM

People on investor roadshows have like 1 to 5 % information retention ...

quartata

@Fatalize triggered

@MarcusAndrews you're missing sigils in your Perl snippet

Marcus Andrews

@ThomasWard Any other distros you like other than Ubuntu?

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

The Quantum Drunkard's Walk code-golfascii-artgrid It is well known that a person on a grid under the influence of alcohol has an equal chance of going in any available directions. However, this common-sense statement does not hold in the realm of very small drunkards, whose behavior is very mu...

Pavel

8:55 PM

I believe I have achieved a new record. An entire 45 minutes after clicking the word icon on my taskbar, MS Word finally opened.

Fatalize

Do the same test with an Android emulator now

Poke

@Pavel you weren't even loading a file?

Fatalize

Report before the end of 2020

Pavel

@Poke No

Poke

yikes

Marcus Andrews

8:56 PM

the android emulator works fine on my end as long as you have the RAM for it

otherwise it just doesn't even want to open sometimes

Pavel

I tried using an Android emulator once.

The same day I bought a used android for $40.

The two events may or may not have been related.

(Nowadays I have my own Pixel that I can use for testing)

Marcus Andrews

what kind of apps have you made?

Pavel

@MarcusAndrews Simple games, mostly.

AdmBorkBork

@Pavel Don't use a potato for a computer? lol ;-)

Pavel

@AdmBorkBork My laptop isn't great but this is totally Word's fault. I got VS open in like 45 seconds.

AdmBorkBork

9:04 PM

Oh, hah

Pavel

(I opened VS by accident, but not the point)

I should take my own advice and uninstall it really

AdmBorkBork

I hear VS is great if your code base is millions of lines, but I've never personally used it.

Unrelated:

> Every software problem is solved through another layer of indirection. Every later of indirection creates a new software problem.

mınxomaτ

@AdmBorkBork Not anymore. We're currently switching devs over to Rider (for a many million lines C# project). VS performance has been degrading since 13 Ultimate

VS remains for Windows driver development. For now.

AdmBorkBork

Huh.

Marcus Andrews

@AdmBorkBork Reminds me of the Hilbert's Hotel problem

Wheat Wizard

9:18 PM

Why has this question suddenly gained so much attention? Its about as old as the site and its definitely not very good.

Fatalize

Wow cool question I'm gonna answer it, thanks for the link!

dzaima

@WheatWizard This challenge was marked as active yesterday - one answer/edit and many will follow

Fatalize

:p

Wheat Wizard

yeah what does active mean though?

dzaima

@WheatWizard codegolf.stackexchange.com/?tab=active

Wheat Wizard

9:22 PM

And where are these people coming from? After half an hour it should be pushed of the active page

Its quite bizarre

Pavel

@AdmBorkBork Yep. Rider is like the best thing ever.

dzaima

@WheatWizard at the bottom of the 1st page the last active question is 23 hours ago, and I wouldn't be surprised if people looked at further pages

Wheat Wizard

Hm things are a lot less active than they used to be

Pavel

@mınxomaτ Just out of curiousity, does Rider support dotnet framework yet, or is your project using Core/Mono?

mınxomaτ

It supports all .NET implementations (core 1, core 2, DotNET any version and Mono)

AdmBorkBork

9:29 PM

@WheatWizard It was linked from the Alphabet Staircase challenge somehow

Wheat Wizard

Ah I guess that might have an effect

wait thats a new challenge

are we back to this now

Pavel

@mınxomaτ Nice. I've been using Rider for a long time, and it used to only allow Core and Mono. I'm glad that it supports Framework now, but as of late I've found that I can make Core projects for everything.

mınxomaτ

My team and me are basically full stack TypeScript now. Looking forward going native again with hobby projects, but in Go - not C#.

Gogland has been nice.

AdmBorkBork

@WheatWizard Alphabet challenges? I hope not.

Mr. Xcoder

@AdmBorkBork Because Powershell hates the alphabet? xD

caird coinheringaahing

9:50 PM

@WheatWizard The quine challenge is older than that :P

Pavel

nonfree.news/2017/09/12/…

caird coinheringaahing

> This is Javascript. The standards have contained confusing and unpredictable edge-case behavior since the language was invented. Changing that now would be ridiculous.

Sounds right :P

Even better

9

Fatalize

ffs I got tricked again by SO's review queue red dot

Magic Octopus Urn

@cairdcoinheringaahing I hope that's satire >_>

caird coinheringaahing

@MagicOctopusUrn Sounds legit to me :P

Pon pon holla mon

10:20 PM

Hello

Any academics here? I assumed codegolf would have some?

Pavel

@MagicOctopusUrn It is, the website's great.

Pon pon holla mon

Hi Pavel

Fatalize

@Ponponhollamon Do Ph.D.students count?

Pon pon holla mon

YUP

lol

Fatalize

Dennis and Luis Mendo are professors at universities

Pon pon holla mon

10:22 PM

O.O

Fatalize

Maybe Peter Taylor too I don't remember

@Ponponhollamon Why do you ask?

Pon pon holla mon

So say there is an exam (taken out of 100) and the maximum on it is 79, the average is 48. Say someone curves the grade, then how would the grade distributions be?

Say the class is made of ~~30-35 people

Fatalize

Not sure I understand what you mean

Magic Octopus Urn

@Ponponhollamon The average was 48 lol? The max was 79? I mean, what did you get? I used to be a TA, my professor would curve that to be a plus 21.

Fatalize

"Someone curves the grade" = ?

caird coinheringaahing

10:26 PM

Um, I think this guy wins PPCG :P

Magic Octopus Urn

@Ponponhollamon It REALLY depends on the professor though.

Pon pon holla mon

Ya it was a crazy test. I'm not sure about curving the grade myself, just heard the prof talk about it and I got interested

I've never heard of it myself, so I thought I'd ask

@MagicOctopusUrn Please elaborate

Fatalize

wtf is curving the grade supposed to mean!?

Magic Octopus Urn

@Ponponhollamon One of my professors would do a +21 flat to all grades, making the max 100, the rest literally +21 to the score. Usually when tests are that low... I mean, it's the teachers fault.

Pavel

@cairdcoinheringaahing Dennis already won PPCG years ago

Magic Octopus Urn

10:29 PM

@Ponponhollamon The other option is this (more common): calcunation.com/calculator/bell%20curve.PNG

Pon pon holla mon

So the person with the highest grade wins, right?

Magic Octopus Urn

The teacher gives the "average" grade a C, and if you're above the average/below the average you go up and down accordingly.

@Ponponhollamon Lol yes, essentially.

@Ponponhollamon If you were the 79, you got an A+ for sure.

Pon pon holla mon

I hate the guy who got the 79 right now

Are there any other techniques to curve the grade?

Magic Octopus Urn

@Ponponhollamon A 48 is still a C, most likely. The ~37 area is when you start getting into D's.

This gives me an idea for a good challenge.

Pon pon holla mon

How many people do you think would have to get grades lower than 48 to get and average like this?

Is this sort of average a result of many people doing averagely or at least some people doing below average?

Luis Mendo

10:42 PM

@StewieGriffin Yes, picking them was fun :-D There are 11 currently

caird coinheringaahing

CMP: What is the most hideous regex you've ever written?

DJMcMayhem

@cairdcoinheringaahing :%s/\v(\<polyline points\=".{-})@<=(\d+),(\d+) (\d+),(\d+)(.*)/\4,\5\6\r<line x1="\2" y1="\3" x2="\4" y2="\5"\/>

Pavel

wat

and how did you find it that fast

DJMcMayhem

Because I wrote it fairly recently

Pavel

Is :%s a variant on the substitute command

DJMcMayhem

10:47 PM

Yeah, it makes the command run on every line

caird coinheringaahing

Mine is definitely this: Kk|(E[^\d ]([\da-f]+)?)|([?SmFvW][^\d]([\da-f]+)?)|([gr].)|([tU]..)|(o.)|('[^']+')|([^\da-‌f? ]([\da-f]+)?)

Luis Mendo

@cairdcoinheringaahing Not sure if hideous, but definitely a monster. It wook me quite a while: github.com/lmendo/MATL/blob/…

caird coinheringaahing

@LuisMendo Is that string matching for MATL?

Luis Mendo

Yes, the MATL parser has quite a few regex's

Pavel

@LuisMendo How can MATL strings have such a complicated regex and still not support multiline strings in any reasonable manner

DJMcMayhem

10:50 PM

IIRC, V's interpreter only uses one regex, and it's not too bad: github.com/DJMcMayhem/V/blob/master/utf8.py#L15

Luis Mendo

@Pavel :-D That's a regex for parsing strings. The parser is complicated

caird coinheringaahing

ಠ_ಠ TFW your regex for checking if a string is a number doesn't recognise 10 or 1.3

Luis Mendo

@Pavel chat.stackexchange.com/transcript/message/41050446#41050446

Pavel

@LuisMendo Why not do what normal languages do and \n.

Luis Mendo

Speaking of monstruous regex's...

531

A: Regex that only matches itself

PCRE flavor, 261 289 210 184 127 109 71 53 51 44 40 bytes Yes, it is possible! <^<()(?R){2}>\z|\1\Q^<()(?R){2}>\z|\1\Q> Try it here. (But / is shown to be the delimiter on Regex101.) Please refrain from making unnecessary edits (updates) on the Regex101 page. If your edit doesn't actually in...

caird coinheringaahing

10:54 PM

@LuisMendo Haha, I tested it and switched to Python flavour. It threw 6 errors then quit :P

Luis Mendo

:-)

@Pavel ¯\_(ツ)_/¯

Destructible Lemon

11:24 PM

I found a possibly interesting koth game

gamecabinet.com/rules/WavingHands.html

Pon pon holla mon

11:46 PM

sooo ... anyone remember me? Can someone answer this: chat.stackexchange.com/transcript/message/41080541#41080541 please

I think Magic Octopus was going to answer this but then he got inspired and went off to write a code challenge

Marcus Andrews

is there a shorter way in Ruby or Python to sum up the alphabet indices of each letter of a word?

s=input()
print(sum(map(ord,s.upper()))-64*len(s))

e.g. Math -> math -> 13 + 1 + 20 + 8 = 42

DJMcMayhem

print(sum(map(lambda c:ord(c)-64,input().upper()))) is close, but one byte longer

Marcus Andrews

ruby or bash perhaps

DJMcMayhem

But if it's for code-golf, you could do lambda s:sum(map(ord,s.upper()))-64*len(s)

Marcus Andrews

nah have to count reading/printing

Pavel

11:55 PM

@MarcusAndrews $><<gets.upcase.map(&:ord).reduce(0,:+)-64*$_.length

Marcus Andrews

says "undefined method `map' "

*undefined method `map' for "MATH":String (NoMethodError)

Pavel

Sorry, I meant gets.upcase.chars.map

Marcus Andrews

someone did 25 in ruby at any rate

no idea how

Pavel

Hmm

Luis Mendo

@MarcusAndrews print(sum(ord(k.upper())-64for k in s))

(1 byte shorter)

DJMcMayhem

11:57 PM

Nice

Marcus Andrews

print(sum(ord(k.upper())-64for k in input()))

46

Luis Mendo

I've sometimes seen map outgolfing list comprehension, but here it's the other way around :-)

Marcus Andrews

somehow possible to cut this in half

Luis Mendo

@MarcusAndrews ?

DJMcMayhem

@MarcusAndrews Specifically in python?

Marcus Andrews

11:59 PM

ruby

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