#include <iostream>

using namespace std;

void solve() {
    int n;
    cin >> n;
    int grid[n][n];
    for (int x = 0; x < n; ++x) {
        for (int y = 0; y < n; ++y) {
            cin >> grid[x][y];
            grid[x][y]--;
        }
    }
    if (n == 1) return;
    vector<pair<int,int>> edges;
    bool trav[n];
    fill(trav, trav + n, false);
    trav[grid[0][0]] = trav[grid[0][1]] = true;
    edges.push_back({grid[0][0], grid[0][1]});
    for (int vi = 2; vi < n; ++vi) {
        int v = grid[0][vi];
        for (int i = 0; i < n; ++i) {
            int u = grid[v][i];
            if (trav[u]) {
                trav[v] = true;
                edges.push_back({v, u});
                break;
            }
        }
    }
    for (const pair<int,int>& e : edges) {
        cout << e.first + 1 << ' ' << e.second + 1 << endl;
    }
}

int main() {
    int t;
    cin >> t;
    while (t--) {
        solve();
    }

    return 0;
}

answer.code: In function ‘void solve()’:
answer.code:16:5: error: ‘vector’ was not declared in this scope
   16 |     vector<pair<int,int>> edges;
      |     ^~~~~~
answer.code:2:1: note: ‘std::vector’ is defined in header ‘<vector>’; did you forget to ‘#include <vector>’?
    1 | #include <iostream>
  +++ |+#include <vector>
    2 | 
answer.code:16:24: error: expected primary-expression before ‘>’ token
   16 |     vector<pair<int,int>> edges;
      |                        ^~
answer.code:16:27: error: ‘edges’ was not declared in this scope
   16 |     vector<pair<int,int>> edges;
      |                           ^~~~~