#include <iostream>
#include <fstream>
using namespace std;
ifstream fin ("pascal.in");
ofstream fout ("pascal.out");
int combinari(int n, int m)
{
    if (m==0)
        return 1;
    else if (m>n)
        return 0;
    else
        return (combinari(n-1,m)+combinari(n-1,m-1));
}

int main()
{
    int n,m;
    fin>>n>>m; //n-linia, m-coloana
    fout<<combinari(n,m);
}