Parenthesis

def solve(n):
  def solve(left, right, x):
    if left == right and right == n:
      print x
      return

    if left < n:
      solve(left + 1, right, x + '(')

    if right < left:
      solve(left, right + 1, x + ')')
  solve(0, 0, '')

import sys
solve(int(sys.argv[1]))