#include <stdio.h>
int memo[100][100]={};
int SuperSum(int k, int n) {
if(k==0) {
// return n;
return memo[k][n];
}
if(memo[k][n]!=0)
{
return memo[k][n];
}
else {
memo[k][n]=SuperSum(k-1, n)+SuperSum(k-1, n-1);
return memo[k][n];
}
}
int main() {
int k, n, u=n;
while( scanf("%d %d", &k, &n) != EOF){
printf("%d\n", SuperSum(k, n));
}
return 0;
}