#include<iostream>
#include <cstdio>
#include <cstdlib>
#include <stack>
#include <algorithm>

using namespace std;

int main()
{
    int i,j,k,l,m,n,o,p,i1,i2,j1,j2;
    int test;
    cin>>test;
    while(test--)
    {
        int r;
        int c;

        cin>>r>>c;
        char a[r][c];
        int k1, k2;
        for(k1=0;k1<r;k1++) {
            for(k2=0;k2<c;k2++) {
                cin>>a[k1][k2];
            }
        }
        int counter=0;

        for(i=0;i<r;i++) {
            for(j=i;j<r;j++) {
                for(k=0;k<c;k++) {
                    for(l=k;l<c;l++) {
                        int rd=j-i;int rc=l-k;
                        if(counter>=(rd+1)*(rc+1))
                        continue;
                        int m=0,n=m+rd;
                        while(n<r)
                        {
                            int o=0,p=o+rc;
                            bool po2=0;
                            while(p<c)
                            {
                                bool po=1;
                                for(i1=i,i2=m;i1<=j;i1++,i2++)
                                for(j1=k,j2=o;j1<=l;j1++,j2++)
                                {if(a[i1][j1]==a[i2][j2] && !(i==m && j==n && k==o && l==p))
                                continue;
                                else
                                {po=0;break;}
                                }
                                if(po)
                                {
                                    counter=max(counter,(rd+1)*(rc+1));
                                    po2=1;
                                    break;
                                }
                                o++;
                                p++;
                            }
                            if(po2) {
                                break;
                            } else {

                            }
                            m++;
                            n++;
                        }
                    }
                }
            }
        }
        cout<< counter <<"\n";
    }
    return 0;
}