#include <bits/stdc++.h>
using namespace std;
// #define int long long
#define endl '\n'

void solve()
{
    int n, m;
    cin >> n >> m;
    pair<int, int> pos[n * m];
    int a[n + 2][m + 2] = {0};
    int le[n + 1], ri[n + 1];
    for (int i = 1; i <= n; i++)
    {
        le[i] = -1;
        ri[i] = 0x3f3f3f;
        for (int j = 1; j <= m; j++)
        {
            cin >> a[i][j];
            pos[a[i][j]] = {i, j};
        }
    }
    int ans = 1;
    // le[pos[0].first] = pos[0].second;
    for (int _ = pos[0].first - 1; _ > 0; _--)
        if (ri[_] < pos[0].second)
            break;
        else
            ri[_] = pos[0].second;
    for (int _ = pos[0].first + 1; _ <= n; _++)
        if (le[_] > pos[0].second)
            break;
        else
            le[_] = pos[0].second;
    for (int i = 1; i < n * m; i++)
    {
        int x, y;
        x = pos[i].first;
        y = pos[i].second;

        if (le[x] == -1)
        {
            if (y > ri[x])
                break;
        }
        else if (ri[x] == 0x3f3f3f)
        {
            if (y < le[x])
                break;
        }
        else
        {
            if (y < le[x] || y > ri[x])
                break;
        }
        for (int _ = x - 1; _ > 0; _--)
            if (ri[_] < y)
                break;
            else
                ri[_] = y;
        for (int _ = x + 1; _ <= n; _++)
            if (le[_] > y)
                break;
            else
                le[_] = y;
        ans = i;
    }
    cout << ++ans << endl;
}

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