#include<iostream>
#include<cstdio>
using namespace std;

long long int i,jaa,k,l,m,n,o,p,i1,i2,jaa1,jaa2;

void solve()
{
long long int r,c;
cin>>r>>c;
char a[r][c];
        for(i=0;i<r;i++)
        for(jaa=0;jaa<c;jaa++)
        cin>>a[i][jaa];
        int ans=0;
        for(i=0;i<r;i++)
        {
            for(jaa=i;jaa<r;jaa++)
            {
                for(k=0;k<c;k++)
                {
                    for(l=k;l<c;l++)
                    {
                        int rd=jaa-i;int rc=l-k;
                        if(ans>=(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<=jaa;i1++,i2++)
                                for(jaa1=k,jaa2=o;jaa1<=l;jaa1++,jaa2++)
                                {if(a[i1][jaa1]==a[i2][jaa2] && !(i==m && jaa==n && k==o && l==p))
                                continue;
                                else
                                {po=0;break;}
                                }
                                if(po)
                                {
                                    ans=max(ans,(rd+1)*(rc+1));
                                    po2=1;
                                    break;
                                }
                                o++;p++;
                            }
                            if(po2)
                            break;
                            m++;n++;
                        }
                    }
                }
            }
        }
        cout<<ans<<"\n";
 
}
int main()
{
	//freopen("/home/magus/Documents/in","r",stdin);

    int t;
    cin>>t;
    while(t--)
    {
	solve();
    }
    return 0;
}