#include <cstdio>

#include <algorithm>

using namespace std;

struct Edge{

    int x, y;

    int dis;

};

int pre[];

int find(int x)

{

    int r = x;

    while (pre[r] != r){

        r = pre[r];

    }

    int i = x, j;

    while (i != r){

        j = pre[i];

        pre[i] = r;

        i = j;

    }

    return r;

}

bool joint(int x, int y)

{

    int xRoot = find(x),

        yRoot = find(y);

    if (xRoot == yRoot)

        return false;

    pre[xRoot] = yRoot;

    return true;

}

bool cmp(Edge e1, Edge e2)

{

    return e1.dis < e2.dis;

}

int main()

{

    int t;

    scanf("%d", &t);

    while (t--){

        int n;

        Edge edge[];

        scanf("%d", &n);

        for (int i = ; i < n; i++){

            pre[i] = i;

        }

        int cnt = ;

        for (int i = ; i < n; i++){

            for (int j = ; j < n; j++){

                int dis;

                scanf("%d", &dis);

                if (i > j)continue;

                edge[cnt].x = i;

                edge[cnt].y = j;

                edge[cnt++].dis = dis;

            }

        }

        sort(edge, edge + cnt, cmp);

        int max = -;

        for (int i = ; i < cnt; i++){

            if (joint(edge[i].x, edge[i].y)){

                max = edge[i].dis > max ? edge[i].dis : max;

            }

        }

        printf("%d\n", max);

    }

    return ;

}