c=9**9
o=[]
i=[o]
def r(x):
v=o
y,*d=x
z,*p=y
t=z!=o
if p==o:
if t: v=[[r(z)]]*c
else:
v=[i]
if t: v+=[[r(z)]+p]
m=0
while p[0]==o:
m+=1
_,*p=p
a,*b=p
for k in x*c:
v=i*m+[v,r(a)]+b
if v[-1]==o: *v,_=v
v=[v]
return v+d
def f(n):
if n:
v=[i*c+[[i]]]
while v!=o:
c*=c
f(n-1)
v=r(v)
print(c)
for k in i*c: f(c)