#include<iostream>
#include<cstring>
using namespace std;int x[100][1000][150],a,b,c,i,j,k,l,sum;
int main(){
	while(true){
		sum=0;
		memset(x,0,sizeof(x));
		cin>>a>>b>>c;if(a==0){break;}
		x[0][0][0]=1;
		for(i=1;i<=b;i++){
			for(j=0;j<=c;j++){
				for(l=0;l<a;l++){
					for(k=l+1;k<=a;k++){
						x[i][j+k][k]+=x[i-1][j][l];
					}
				}
			}
		}
		for(i=0;i<=a;i++){sum+=x[b][c][i];}
		cout<<sum<<endl;
	}
}