magics

#include <iostream>
#include <vector>
using namespace std;

int main() {
    int n;
    while (cin >> n) {
        bool magic = true;
        int suma = 0;
        int diag = 0;
        int diag2 = 0;
        vector< vector<int> > C(n, vector<int>(n));
        vector<bool> aparicio(n*n, false);
        vector<int> sumcol(n, 0);
        for (int i = 0; i < n; ++i) {
            int sumfil = 0;
            for (int j = 0; j < n; ++j) {
                cin >> C[i][j];
                if (aparicio[C[i][j]-1]) magic = false;
                else aparicio[C[i][j]-1] = true;
                sumfil = sumfil + C[i][j];
                sumcol[j] = sumcol[j] + C[i][j];
                if (i == 0) suma = suma + C[0][j];
                if (i == j) diag = diag + C[i][i];
                if (j == n-1-i) diag2 = diag2 + C[i][n-1-i];
            }
            if (sumfil != suma) magic = false;
        }
        if (diag != suma) magic = false;
        if (diag2 != suma) magic = false;
        int k = 0;
        while (k < n and magic) {
            if (sumcol[k] != suma) magic = false;
            ++k;
        }
		if (magic) cout << "si" << endl;
        if (not magic) cout << "no" << endl;
    }
}