URI Online Judge | 1153

Simple Factorial

Adapted by Neilor Tonin, URI Brazil

Timelimit: 1

Read a value N. Calculate and write its corresponding factorial. Factorial of N = N * (N-1) * (N-2) * (N-3) * ... * 1.

Input

The input contains an integer value N (0 < N < 13).

Output

The output contains an integer value corresponding to the factorial of N.

Input Sample Output Sample

4

24