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

int main() {
	int n;
	cin >> n;
	vector<vector<int>> graph(n, vector<int>(n));
	for (auto& line : graph) {
		for (auto& element : line) {
			cin >> element;
		}
	}
	
	vector<pair<int, int>> graph_2;
	
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (i >= j) {
				continue;
			}
			
			if (graph[i][j] == 1) {
				graph_2.emplace_back(i, j);
			}
		}
	}
	
	for (auto& [x, y] : graph_2) {
		cout << x + 1 << " " << y + 1 << endl;
	}
	
	return 0;
}