Олимпиадный тренинг

Задача 38688. Number of combinations


Задача

Темы: Цикл for
Given natural n and k compute the value of \(C^k_n = {n! \over k!(n-k)!} \) (number of combinations of n elements by k).

Input
2 numbers are entered - n and k (n, k ≤ 30 ).

Imprint
You need to output  value \(C^k_n\) (integer).
 
Examples
# Input Output
1 2
1
2