Problem Statement:
the product of an integer and all the integers below it; e.g. factorial four ( 4! ) is equal to 1x2x3x4 = 24.

Input Format:
Given a number x between 1 and 52 inclusive

Output Format:
print the factorial of x

Sample Input:

Sample Output:

Added by: gammal
Added at: 2015-06-14 14:00:00 UTC
Time Limit: 1 second
Partial score: No