#include<fstream.h>
ifstream f("combinari.in");
ofstream g("combinari.out");
int n,k;
int comb(int n,int k)
{if(k==0) return 1;
	if(k==n) return 1;
		if(k==1) return n;
	return comb(n-1,k)+comb(n-1,k-1);
}
int comb1(int n,int k){
	if(k==0) return 1;
	return ((n-k+1)*comb1(n,k-1));
}
int main()
{f>>n>>k;
 g<<comb(n,k);
return 0;
}