func_code_string: #include <bits/stdc++.h>   int main() {     int n;     std::cin >> n;     int a[n][n];     for (int i = 0; i < n; i++)       for (int j = 0; j < n; j++) std::cin >> a[i][j];     int sum = 0;     int l = (n - 1) / 2, j = n - 1;     for (int i = 0; i < n; i++) {       sum = sum + a[i][l] + a[l][i] + a[i][i] + a[i][j--];     }     sum = sum - 3 * a[l][l];     std::cout << sum;   }   