zoj 2284

#include <cstdio>
#include <iostream>
#include <algorithm>
using namespace std;

long long  yanghui[22][222] = {0};

void init()
{
    int row,column;
    
    for(row = 1; row < 20; ++ row){
        yanghui[row][0] = 1;
        for(column = 0; yanghui[row][column] > 0; ++column){
            for(int i = 0;i <= row; ++i){
                yanghui[row + 1][column + i] += yanghui[row][column];
            }
        }
    }
    return ;
}

int main()
{
    init();
    int n,k;
    while(cin >> n >> k && (n || k)){
        printf("%lld\n",yanghui[n][k]);
    }
    return 0;
}