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   else28     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 }