Factorial n (n!)

Time Limit: 1 sec

 

The Problem

Factorial n is written as n! and n! = 1∗2∗3∗. . .∗(n−1)∗n.

For example,

0! = 1

1! = 1

2! = 1 x 2 = 2

3! = 1 x 2 x 3 = 6

4! = 1 x 2 x 3 x 4 = 24

5! = 1 x 2 x 3 x 4 x 5 = 120

etc.

  

Given an integer number n, you will have to find out the value of n!.

 

The Input

Input file contain a series of line, each line contain one integer numbers n (0<=n<20. Input is terminated by EOF.

 

The Output

For each line of input, output will show the value of n! in a separate line.

 

Sample Input

3

5

9

 

Sample Output

6

120

362880

 

 

 

 

Problem Setter: Shahin ShamS