/*
 *
 ********************************************************************************************
 * AUTHOR : Vijju123                                                                        *
 * Language: C++14                                                                          *
 * Purpose: -                                                                               *
 * IDE used: Codechef IDE.                                                                  *
 ********************************************************************************************
 *
 Comments will be included in practice problems if it helps ^^
 */



#include <iostream>
#include<bits/stdc++.h>
using namespace std;
int n;
int arr[110][110];

//Returns trace. Takes starting point, and length of square sub-matrix as input
int findTrace(int i,int j,int k)
{
    int trace=0,l;
    for(l=0;l<=k;l++)
    {
        trace+=arr[i+l][j+l];
    }
    return trace;
}

int main() {
	// your code goes here
	#ifdef JUDGE
    freopen("input.txt", "rt", stdin);
    freopen("output.txt", "wt", stdout);
    #endif
	ios_base::sync_with_stdio(0);
	cin.tie(NULL);
	cout.tie(NULL);
	int t;
	cin>>t;
	while(t--)
	{
	    //input
	    int i,j;
	    cin>>n;
	    
	    for(int i=0;i<n;i++)
	    {
	        for(int j=0;j<n;j++)
	            cin>>arr[i][j];
	    }
	    
	    int k,l,trace=0;
	    for(i=0;i<n;i++)
	    {
	        for(j=0;j<n;j++)
	        {
	            for(k=0;i+k<n and j+k<n;k++)
	            {
	                trace=max(trace,findTrace(i,j,k));//Check trace of every sub-matrix. Print the maximum one.
	            }
	        }
	    }
	    cout<<trace<<endl;
	}
	
	return 0;
}