#include <bits/stdc++.h>

using i64 = int64_t;

namespace stdr = std::ranges;
namespace stdv = std::views;

void solve() {
    int n;
    std::cin >> n;

    std::vector a(n, std::vector<int>(n));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            std::cin >> a[i][j];
            a[i][j]--;
        }
    }

    if (n == 1) {
        return;
    }

    std::set<std::pair<int, int>> S;

    for (auto b : a) {
        if (b[0] > b[1]) {
            std::swap(b[0], b[1]);
        }
        S.emplace(b[0], b[1]);
    }

    if (n > 2) {
        for (auto b : a) {
            int x = b[0];
            int y = b[1];
            int z = b[2];
            if (a[y][1] != x) {
                continue;
            }
            if (a[x][2] == a[y][2]) {
                int w = (stdr::find(a[z], x) < stdr::find(a[z], y) ? x : y);
                if (w > z) {
                    std::swap(w, z);
                }
                S.emplace(w, z);
            }
            else {
                if (z > x) {
                    std::swap(z, x);
                }
                S.emplace(z, x);
            }
        }
    }
    assert(S.size() <= n - 1);

    for (auto [x, y] : S) {
        std::cout << x + 1 << " " << y + 1 << "\n";
    }
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    int t;
    std::cin >> t;

    while (t--) {
        solve();
    }

    return 0;
}