Binomial Showdown

Time Limit: 1 Second    Memory Limit: 32768 KB

In how many ways can you choose k elements out of n elements, not taking order into account?

Write a program to compute this number.

Input

The input will contain one or more test cases.

Each test case consists of one line containing two integers n (n >= 1) and k (0 <= k <= n).

Input is terminated by two zeroes for n and k.

Output

For each test case, print one line containing the required number. This number will always fit into an integer, i.e. it will be less than 2^31.

Sample Input

4 2
10 5
49 6
0 0

Sample Output

6
252
13983816

Submit

Source: University of Ulm Local Contest 1997