kaijo.py

# coding:utf-8

import sys

def Kaijo(num):
  if num == 0:
    return 1
  else:
    return Kaijo(num -1) * num

if __name__ == '__main__':
  if len(sys.argv) > 1:
    if sys.argv[1].isdigit():
      k = int(sys.argv[1])
      sys.setrecursionlimit(k + 2)
      print Kaijo(k)
    else:
      print 'number please'
  else:
      print 'number please'