#include <iostream>

using namespace std;

long long cnk(long long n, long long k)
{
  long long res = 1;
  if (k > n - k) k = n - k;
  for(long long i = 1; i <= k; i++)
    res = res * (n - i + 1) / i;
  return res;
}

int main()
{
	long long x,y;
	while(cin>>x>>y&&(x||y))
	{
		cout << cnk(x+y,x) << endl;
	}
}