Write a program, which repeatedly reads in a non-negative integer N followed by a second non-negative integer K, and prints out the number of ways you can choose K items from among N total items. We call this "N-choose-K", and the formula for "N-choose-K" is:

N! / (K! * (N-K)!)

Input Format:
The input consists of two integers N and K respectively.

Output Format:
The output contains a single integer indicating the result given the integers N and K.

Constraints:
0 ≤ K ≤ N