#include<iostream>
using namespace std;
int comm(int n,int k)
{
if(k>n) return 0;
else if(k==n||k==0) return 1;
else return comm(n-1,k)+comm(n-1,k-1);
}
int main(){
int k,n;
cin>>n>>k;
cout<<"C(n,k)="<<comm(n,k)<<endl;

return 0;
}