func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m, x;   void ans(int x1, int x2, int y1, int y2, int now) {     if (x1 + 1 > x2 - 1 || y1 + 1 > y2 - 1) {       cout << 0;       return;     } else {       if (now + 1 == x) {         if ((x2 - x1 - 1) == 1 || (y2 - y1 - 1) == 1) {           if ((x2 - x1 - 1) == 1 && (y2 - y1 - 1) == 1)             cout << 1;           else             cout << ((x2 - x1 - 1) + (y2 - y1 - 1) - 1) / 2;         } else           cout << ((x2 - x1 - 1) + (y2 - y1 - 1) - 2);       } else         ans(x1 + 1, x2 - 1, y1 + 1, y2 - 1, now + 1);     }   }   int main() {     cin >> n >> m >> x;     if (n == 1 || m == 1) {       if (n == 1 && m == 1) {         if (x == 1) {           cout << 1;         } else           cout << 0;         return 0;       }       if (x == 1) {         cout << (n + m) / 2;       } else         cout << 0;       return 0;     }     if (x == 1) {       cout << (n + m - 2);       return 0;     }     ans(1, n, 1, m, 1);     return 0;   }   