#include <bits/stdc++.h>
// iostream is too mainstream
#include <cstdio>
// bitch please
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <list>
#include <cmath>
#include <iomanip>
#include <time.h>
#define dibs reserve
#define OVER9000 1234567890123456789LL
#define ALL_THE(CAKE,LIE) for(auto LIE =CAKE.begin(); LIE != CAKE.end(); LIE++)
#define tisic 47
#define soclose 1e-8
#define chocolate win
// so much chocolate
#define patkan 9
#define ff first
#define ss second
#define abs(x) (((x) < 0)?-(x):(x))
#define uint unsigned int
#define dbl long double
#define pi 3.14159265358979323846
using namespace std;
// mylittledoge

using cat = long long;

#ifdef DONLINE_JUDGE
	// palindromic tree is better than splay tree!
	#define lld I64d
#endif

int main() {
	cin.sync_with_stdio(0);
	cin.tie(0);
	cout << fixed << setprecision(10);
	int T;
	cin >> T;
	for(int t = 0; t < T; t++) {
		int N, M;
		cin >> N >> M;
		vector< vector<int> > G(N, vector<int>(M));
		for(int i = 0; i < N*M; i++) cin >> G[i/M][i%M];
		vector< vector<cat> > mx_up(N, vector<cat>(M));
		vector< vector<cat> > mx_down(N, vector<cat>(M));
		vector< vector<cat> > mx_lft(N, vector<cat>(M));
		vector< vector<cat> > mx_rt(N, vector<cat>(M));
		for(int i = 0; i < N; i++) {
			cat mi = 0, sum = 0;
			for(int j = 0; j < M; j++) {
				if(j > 0) mx_lft[i][j] = sum-mi;
				mi = min(mi, sum);
				sum += G[i][j];
			}
			mi = sum = 0;
			for(int j = M-1; j >= 0; j--) {
				if(j < M-1) mx_rt[i][j] = sum-mi;
				mi = min(mi, sum);
				sum += G[i][j];
			}
		}
		for(int i = 0; i < M; i++) {
			cat mi = 0, sum = 0;
			for(int j = 0; j < N; j++) {
				if(j > 0) mx_up[j][i] = sum-mi;
				mi = min(mi, sum);
				sum += G[j][i];
			}
			mi = sum = 0;
			for(int j = N-1; j >= 0; j--) {
				if(j < N-1) mx_down[j][i] = sum-mi;
				mi = min(mi, sum);
				sum += G[j][i];
			}
		}
		cat ans = -OVER9000;
		for(int i = 1; i < N-1; i++) for(int j = 1; j < M-1; j++)
			ans = max(ans, G[i][j] + mx_down[i][j] + mx_up[i][j] + mx_lft[i][j] + mx_rt[i][j]);
		cout << ans << "\n";
	}
	return 0;}

// look at my code
// my code is amazing