func_code_string: #include <bits/stdc++.h>   using namespace std;   long long n, m, k;   long long ans;   int main() {     cin >> n >> m >> k;     if (k > n + m - 2) {       cout << -1 << endl;       return 0;     }     if (k > n - 1) {       long long x = k;       x -= (n - 1);       ans = m / (x + 1);     } else       ans = n / (k + 1) * m;     if (k > m - 1) {       long long x = k;       x -= (m - 1);       ans = max(ans, (n / (x + 1)));     } else       ans = max(ans, (m / (k + 1) * n));     cout << ans << endl;     return 0;   }   