func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int w, h, k, sum = 0;     cin >> w >> h >> k;     while (k != 0) {       sum = sum + ((2 * w) + (2 * h) - 4);       w = w - 4;       h = h - 4;       k = k - 1;     }     cout << sum;   }   