// Program 77: Doubly Markov Matrix

import java.util.*;
class DoublyMarkov {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        if (n < 1 || n > 9) {
            System.out.println("INVALID ORDER");
            return;
        }
    double[][] a = new double[n][n];
    boolean ok = true;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            a[i][j] = sc.nextDouble();
            if (a[i][j] < 0) {
                ok = false;
            }
    }
}
for (int i = 0; i < n; i++) {
    double row = 0, col = 0;
    for (int j = 0; j < n; j++) {
        row += a[i][j];
        col += a[j][i];
    }
if (Math.abs(row - 1.0) > 0.0001 || Math.abs(col - 1.0) > 0.0001) {
    ok = false;
}
}
System.out.println(ok ? "DOUBLY MARKOV MATRIX" : "NOT A DOUBLY MARKOV MATRIX");
}
}