#include <bits/stdc++.h>   using namespace std;   int main() {     int a, b = 1, c = 2, o = 1, j, k;     cin >> a;     int p = a / 2;     for (k = 0; k < a; k++) {       for (j = 0; j < p; j++) {         cout << c <<    ;         c += 2;       }       for (j = 0; j < a - p * 2; j++) {         cout << b <<    ;         b += 2;       }       for (int j = 0; j < p; j++) {         cout << c <<    ;         c += 2;       }       cout << endl;       if (p == 0) o = 0;       if (o == 0)         p++;       else         p--;     }     return 0;   }   