#include <fstream>

#define NMax 110
#define INF 1000000000

using namespace std;

ifstream f("royfloyd.in");
ofstream g("royfloyd.out");

int nodes, edges, distances[NMax][NMax], inter[NMax][NMax];

int getmin(int a, int b)
{
	if (a < b)
		return a;
	return b;
}

void recons(int i, int j)
{
	if (inter[i][j] == 0)
		g << i << " " << j<<"\n";
	else {
		recons(i, inter[i][j]);
		recons(inter[i][j], j);
	}
}

int main()
{
	f >> nodes;

	int n1 = 0, n2 = 0;
	for (int i = 1; i <= nodes; i++) {
		for (int j = 1; j <= nodes; j++) {
			f >> distances[i][j];

			if (!distances[i][j])
				distances[i][j] = INF;
		}
	}

	for (int k = 1; k <= nodes; k++) {
		for (int i = 1; i <= nodes; i++) {
			for (int j = 1; j <= nodes; j++) {

				if (i == j)
					continue;
				distances[i][j] = getmin(distances[i][j], distances[i][k] + distances[k][j]);

				if (distances[i][j] == distances[i][k] + distances[k][j])
					inter[i][j] = k;

			}
		}
	}

	for (int i = 1; i <= nodes; i++)
		for (int j = 1; j <= nodes; j++)
			if (distances[i][j] == INF)
				distances[i][j] = 0;

	for (int i = 1; i <= nodes; i++) {
		for (int j = 1; j <= nodes; j++)
			g << distances[i][j] << " ";
		g << "\n";
	}

	recons(1, 4);

	return 0;
}