#include <bits/stdc++.h>   using namespace std;   long long funk(long long x, long long y) {     bool used[10000];     long long res = 1;     for (long long i = 1; i <= 100; i++) used[i] = 0;     for (long long i = x + 1; i <= y; i++) {       res *= i;       for (long long j = 2; j <= y - x; j++) {         if (!used[j] && res % j == 0) {           res /= j;           used[j] = 1;         }       }     }     return res;   }   int main() {     long long n, m, t, i, j;     cin >> n >> m >> t;     long long s = 0;     for (i = 4; i < t && i <= n; i++) {       if (t - i <= m) {         s += (funk(i, n) * funk(t - i, m));       }     }     cout << s <<   n ;   }   