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ZOJ Problem Set - 1938
Binomial Showdown

Time Limit: 2 Seconds      Memory Limit: 65536 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


Source: University of Ulm Local Contest 1997
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