func_code_string: #include <bits/stdc++.h>   using namespace std;   void solve();   int main() {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     ;     solve();     return 0;   }   void solve() {     long long n;     cin >> n;     long long mat[n][n];     for (int i = 0; i < n; i++) {       for (int j = 0; j < n; j++) {         cin >> mat[i][j];       }     }     long long mid_row = (n - 1) / 2;     long long sum = 0;     for (int i = 0; i < n; i++) {       if (i != mid_row) {         sum += mat[i][i];         sum += mat[i][mid_row];         sum += mat[i][(n - 1) - i];       }     }     for (int i = 0; i < n; i++) {       sum += mat[mid_row][i];     }     cout << sum <<   n ;   }   