#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define pii pair<int, int>
#define ll long long
using namespace std;

map<pii,int> mp;
void solve(){
    int n;
    cin>>n;
    mp.clear();
    int a[n + 1][n + 1]{};
    int adr[n + 1][n + 1]{};
    int vis[n + 1][n + 1]{};
    int noleaf[n + 1]{};
    vector<int> edge[n + 1]{};
    set<pii> q;
    auto insert = [&](int u, int v)
    {
        q.insert({min(u, v), max(u, v)});
    };
    for (int i = 1;i<=n;i++){
        for(int j=1;j<=n;j++)
            cin >> a[i][j], adr[i][a[i][j]] = j;
        for(int j=1;j<n;j++)
            edge[a[i][j]].pb(a[i][j + 1]);
        insert(a[i][1], a[i][2]);
    }
    if(n==2){
        cout <<"1 2\n";
        return;
    }
    set<pii> ans;
    while(!q.empty()){
        auto [u, v] = *q.begin();
        q.erase(q.begin());
        int flag1 = 0;
        int flag2 = 0;
        for (int i = 1; i <= n; i++)
        {
            if (i == u || i == v)
                continue;
            flag1 += adr[i][u] < adr[i][v];
            flag2 += adr[i][u] > adr[i][v];
        }
        if(flag1)noleaf[u]=1;
        if(flag2)noleaf[v]=1;
    }
    for (int i = 1;i<=n;i++){
        vector<int>now;
        now.pb(i);
        for(int j=2;j<=n;j++)
        {
            now.pb(a[i][j]);
            if(noleaf[a[i][j]]==0){
                for (int k = 0; k < now.size() - 1;k++)
                    ans.insert({min(now[k], now[k + 1]), max(now[k], now[k + 1])});
                    now.clear();
            }
        }
    }
    for (auto [u, v] : ans)
        cout << u << " " << v << '\n';
}

signed main() {
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    int t;
    cin>>t;
    while(t--)
        solve();
    return 0;
}