>>> from random import randint as r
>>> [r(0,99) for k in range(10)]
[75, 92, 73, 84, 26, 20, 10, 94, 53, 12]
>>> [r(0,99) for k in range(10)]
[41, 33, 53, 36, 44, 61, 98, 41, 6, 25]

a=27,b=-1 -> 27
a=-7,b=-5 -> 35
a=-7,b=5 -> 5
a=0,b=1 -> 1

>>> def steps_before_cycle(n):
...     seen = [n]
...     while f(n) not in seen:
...         n = f(n)
...         seen.append(n)
...     i = seen.index(f(n))
...     return i

>>> [steps_before_cycle(n) for n in range(25)]
[0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 6, 4, 5, 3, 3, 5, 4, 6, 2, 1, 2, 6]

>>> all(cycle_len(n) == 1 for n in range(1012))
True
>>> all(cycle_len(n) == 1 for n in range(1013))

# output random values from 1 to 7, inclusive
my randval;
my rand = 1;
do {
  do {
    call rand = random(rand).state;
    randval = rand & 7;
  } while(randval < 1);
  display = randval;
} while (1);

sub random(state, shifted) {
  shifted = state << 1;
  state ^= shifted;
  shifted = state >>> 5;
  state ^= shifted;
  shifted = state << 2;
  state ^= shifted;
}