#!/usr/bin/python3

"""Print the parenthesized expressions up to length 6."""

import itertools

def parens(n,s):
    if n == 1:
        return [s]
    return itertools.chain.from_iterable(
        [itertools.product(parens(k,s),parens(n-k,s+k)) for k in range(1,n)])

for n in range(7):
    for p in parens(n,0):
        print (p)