#include <bits/stdc++.h>
#define endl '\n'
#define int long long
#define x first
#define y second
using namespace std;
typedef pair<int, int> PII;

void solve() {
    int n, m;
    cin >> n >> m;
    vector< vector<int> > g( n + 1, vector<int>(m + 1) );
    vector<PII> pos(n * m);
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> g[i][j];
            pos[ g[i][j] ] = {i, j};
        }
    }
    vector<PII> lr( n + 2, { m + 1, 0 } );
    int i;
    for (i = 0; i < n * m; i++) {
        auto [x, y] = pos[i];
        if ( y >= lr[x - 1].y && y <= lr[x + 1].x ) {
            lr[x].x = min( lr[x].x, y );
            lr[x].y = max( lr[x].y, y );
        } else {
            break;
        }
    }
    cout << i << endl;
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int t = 1;
    cin >> t;
    while (t--) solve();
    return 0;
}