#!/usr/bin/env python
# -*- coding: utf-8 -*-

# rfactorial.py
# Recursive implementation of factorial.
#
# Author: Billy Wilson Arante
# Created: 2016/06/20 PHT

from sys import argv

def factorial(number):
    """Recursive factorial"""

    if number <= 1:
        return 1
    else:
        return number * factorial(number - 1)

def test():
    """Driver function"""

    for i in range(11):
        print "%d! = %d" % (i, factorial(i))

def main():
    """Main"""

    number = argv[1]
    print factorial(int(number))


if __name__ == "__main__":
    main()
