#include<iostream>
#include<math.h>
using namespace std;

const int N = 1e4;

bool used[N][N];

int a[N][N];
int answer[2 * N];

int main()
{
    int n;
    cin >> n;
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < n; ++j)
            cin >> a[i][j];
    int cnt = 0;
    for (int j = 0; j < n; ++j)
        for (int i = 0; i < n; ++i)
            {
                int cur = a[i][j];
                if (used[j][cur] == true)
                    {
                        for (int k = 0; k < i; k++)
                            if (a[k][j] == cur)
                                {
                                    answer[cnt++] = k;
                                    break;
                                }
                        answer[cnt++] = i;
                        break;
                    }
                else
                    used[j][cur] = true;
            }
    for (int i = 0; i < cnt; i += 2)
        cout << answer[i] + 1<< ' ' << answer[i + 1] + 1 << endl;
}