3
2
1 2
2 1
5
1 4 5 3 2
2 3 4 1 5
3 4 2 5 1
4 3 1 5 2
5 4 3 1 2
3
1 3 2
2 1 3
3 1 2

2 1 

2 3
3 4
5 4
4 1 

2 1
3 1

#include<bits/stdc++.h>

#define rep(i,a,b) for(int i=a;i<=b;i++)

using namespace std;

const int maxn=;

int a[maxn][maxn],vis[maxn];

int main()

{

    int T,N;

    scanf("%d",&T);

    while(T--){

        scanf("%d",&N);

        rep(i,,N) rep(j,,N) scanf("%d",&a[i][j]);

        int now=N;

        while(true){

            int x=a[][now],y=;

            while(vis[a[x][y]]) y++;

            printf("%d %d\n",a[x][y],x);

            vis[x]=; now--;

            if(now==) break;

        }

        puts("");

        memset(vis,,sizeof(vis));

    }

    return ;

}