func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n = 0, m = 1, i = 0, j = 0, k = 0, x = 0;     int area[51][51] = {0};     cin >> n;     for (i = 0; i < n; i++)       for (x = 0; x < n; x++) cin >> area[i][x];     for (i = 0; i < n; i++)       for (x = 0; x < n; x++)         if (area[i][x] != 1) {           m = 1;           for (j = 0; j < n; j++) {             if (j == i) continue;             for (k = 0; k < n; k++) {               if (k == x) continue;               if (area[i][x] == area[j][x] + area[i][k]) {                 m = 0;                 break;               }             }             if (m == 0) break;           }           if (m == 1) {             cout <<  NO  << endl;             return 0;           }         }     cout <<  YES  << endl;     return 0;   }   