// compile: g++ -o data data.cpp -O3 -std=gnu++20 -Wall -Wextra -Wshadow -D_GLIBCXX_ASSERTIONS -ggdb3 -fmax-errors=2 -DLOCAL
// run: ./data < data.in
#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#ifdef LOCAL
#include <debug/codeforces.h>
#define debug(x...) _debug_print(#x, x);
// #define debug(x...) {_variables(#x);_print(x);}
#else
#define debug(x...)
#endif
template<typename...Args> void print_(Args...args){((cout<<args<<" "),...)<<endl;}
#define rep(i,a,b) for(int i=(a);i<(int)(b);++i)
#define sz(v) ((int)(v).size())
#define print(...) print_(__VA_ARGS__);
#define INTMAX (int)(9223372036854775807)
#define INTINF (int)(1152921504606846976)
#define int long long
#define MAXN 1010

int mp[MAXN][MAXN];
int h, w;
const int dir[4][2] = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};

struct graph {
    struct node {
        int u, v, w;
    };
    vector<vector<node>> e;
    int n, m;
    bool directed;
    graph(int V, bool D = 0) {
        n = V;
        e.resize(n);
        directed = D;
    }
    void add_edge(int u, int v, int w = 1) {
        e[u].push_back(node{u, v, w});
        ++m;
    }
    void graphviz_dump(string filename = "graph.dot") {
        ofstream gf;
        gf.open(filename);
        gf << (directed ? "digraph" : "graph") << " {\n";
        gf << "    "; rep(i, 0, n) gf << i << " ;"[i==n-1]; gf << endl;
        string notation = directed ? " -> " : " -- ";
        for (auto es: e) {
            for (auto edge: es) {
                gf << "    " << edge.u << notation << edge.v << (directed ? " ;\n" : ";\n");
            }
        }
        gf << "}\n";
    }
    int dfs(vector<bool> &vis, int k) {
        vis[k] = 1;
        int ans = mp[k/w][k%w];
        for (auto edge: e[k]) {
            if (!vis[edge.v]) ans += dfs(vis, edge.v);
        }
        return ans;
    }
};

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);

    int _; cin >> _;
    while (_--) {
        cin >> h >> w;
        rep(i, 0, h) rep(j, 0, w) cin >> mp[i][j];
        graph g(h*w);
        rep(i, 0, h) {
            rep(j, 0, w) {
                if (!mp[i][j]) continue;
                rep(k, 0, 4) {
                    int dx = i + dir[k][0], dy = j + dir[k][1];
                    if (dx<0 || dx>=h || dy<0 || dy>=w) continue;
                    g.add_edge(i*w+j, dx*w+dy);
                }
            }
        }
        vector<bool> vis(h*w, 0);
        int ans = 0;
        rep(i, 0, h*w) {
            if (vis[i]) continue;
            ans = max(ans, g.dfs(vis, i));
        }
        cout << ans << endl;
    }

    return 0;
}