//homogeneous.cpp
//author Malte Spiess

#include <algorithm>
#include <cassert>
#include <fstream>
#include <iostream>
#include <string>

using namespace std;

#define MAXROW 1000

int main() {

  ifstream in("homogeneous.in");

  int sq[MAXROW][MAXROW];

  bool geht = true;

  int n;

  while (in >> n && n > 0) {

    for (int i = 0; i < n; i++)
      for (int j = 0; j < n; j++) {
	in >> sq[i][j];
	  }

    int top;

    for (int i = 0; i < n - 1; i++) 
      for (int j = i + 1; j < n; j++) {
	top = sq[0][i] - sq[0][j];
	for (int k = 1; k < n; k++) 
	    if (sq[k][i] - sq[k][j] != top) {
	      geht = false;
	      i = j = k = n;
	    }
      }

    if (!geht)
      cout << "not ";

    cout << "homogeneous" << endl;

  }

  return 0;
}