#include <bits/stdc++.h>
using namespace std;

#ifdef CKISEKI
#define safe cerr<<__PRETTY_FUNCTION__\
    <<" line "<<__LINE__<<" safe\n"
#define debug(a...) debug_(#a, a)
#define orange(a...) orange_(#a, a)
using std::cerr;
template <typename ...T>
void debug_(const char *s, T ...a) {
    cerr << "\e[1;32m(" << s << ") = (";
    int cnt = sizeof...(T);
    (..., (cerr << a << (--cnt ? ", " : ")\e[0m\n")));
}
template <typename I>
void orange_(const char *s, I L, I R) {
    cerr << "\e[1;32m[ " << s << " ] = [ ";
    for (int f = 0; L != R; ++L)
        cerr << (f++ ? ", " : "") << *L;
    cerr << " ]\e[0m\n";
}
#else
#define safe ((void)0)
#define debug(...) ((void)0)
#define orange(...) ((void)0)
#endif

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int T;
    cin >> T;
    while (T--) {
        int n, m;
        cin >> n >> m;

        vector<vector<int>> a(n, vector<int>(m));
        vector<tuple<int,int,int>> t;
        set<pair<int,int>> st;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                cin >> a[i][j];
                t.emplace_back(a[i][j], i, j);
            }
        }

        sort(t.begin(), t.end());
        st.insert({ -1, -1 });
        st.insert({ n+1, m+1 });
        int ans = 0;
        for (auto [val, i, j]: t) {
            auto [it, succ] = st.insert({ i, j });
            if (j > prev(it)->second && j > next(it)->second) {
                break;
            }
            if (j < prev(it)->second && j < next(it)->second) {
                break;
            }
            if (i > prev(it)->first && i > next(it)->first) {
                break;
            }
            if (i < prev(it)->first && i < next(it)->first) {
                break;
            }

            ans = val + 1;
        }
        cout << ans << '\n';

    }
    return 0;
}