#include<stdio.h>

int main(){
 int q,w,e,r,t,y;
 int i,j,k;
 int dp[21][11][156];
 
 dp[0][0][0] = 1;
 
 for(i = 1;i < 21;i++){
  dp[i][0][0]=1;
  for(j = 1;j < 11;j++){
   for(k = 1;k < 156;k++){
    dp[i][j][k] = (n<=s ? dp[i-1][j-1][k-i] : 0) + dp[i-1][j][k];
}}}

 while(scanf("%d%d%d",&q,&w,&e),q){
  printf("%d\n",dp[q][w][e]);
 }
 return 0;
}