Extra long factorials

Problem Statement

You are given an integer N. Print the factorial of this number.

N!=N×(N−1)×(N−2)×⋯×3×2×1

Note: Factorials of N>20 can't be stored even in a 64−bit long long variable. Big integers must be used for such calculations. Languages like Java, Python, Ruby etc. can handle big integers but we need to write additional code in C/C++ to handle such large values.

We recommend solving this challenge using BigIntegers.

Input Format Input consists of a single integer N.

Constraints 1≤N≤100

Output Format Output the factorial of N.

Sample Input 25

Sample Output 15511210043330985984000000