#!/usr/bin/python

def silnia(n):
    if n<=1:
        return 1
    else:
        return n*silnia(n-1)

if __name__=="__main__":
    import sys
    print sys.argv
    if len(sys.argv)<2:
        print "please give me an argument"
    else:
        print "the factorial of",sys.argv[1],"equals",silnia(int(sys.argv[1]))
else:
    print "efekt uboczny", __name__