1 #include <iostream>
2 #include <cstdio>
3 #include <cstring>
4 #include <cmath>
5 #include <algorithm>
6 #include <string>
7 #include <vector>
8 #include <map>
9 #include <set>
10 #include <time.h>
11 #include <queue>
12 #include <stack>
13 #include <cctype>
14 #include <utility>
15 #include <numeric>
16 #include <cstdlib>
17 #include <functional>
18 #include <iomanip>
19 #include <sstream>
20 using namespace std;
21 int n,k,s;
22 int ans;
23 void gao(int now,int deep,int sum)
24 {
25 if(deep==k&&sum==s) {ans++;return ;}
26 if(deep>k||sum>s) return ;
27 else
28 for(int i=now+1;i<=n;i++)
29 gao(i,deep+1,sum+i);
30 return ;
31 }
32 int main()
33 {
34
35 while(scanf("%d%d%d",&n,&k,&s)!=EOF)
36 {
37 if(n+k+s==0) break;
38 ans=0;
39 for(int i=1;i<=n;i++)
40 gao(i,1,i);
41 printf("%d\n",ans);
42 }
43 return 0;
44 }
