// Program by Poorvak_001,zero_logic,boxer_1
    #include<cstdio>
    #include<iostream>
    #include <cmath>
    #include <vector>
    #include <algorithm>
       
    using namespace std;
     
    int main()
    {
    int i,j,k,l;
    int m,n,o,p;
    int i1,i2,j1,j2;
    int T;
    scanf("%d",&T);
    while(T--)
    {
    int r,c;
    scanf("%d%d",&r,&c);
    char a[r][c];
    for(i=0;i<r;i++)
    for(j=0;j<c;j++)
	cin>>a[i][j];
    int ans=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(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<=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)
    {
    ans=max(ans,(rd+1)*(rc+1));
    po2=1;
    break;
    }
    o++;p++;
    }
    if(po2)
    break;
    m++;n++;
    }
    }
    }
    }
    }
    printf("%d\n",ans);
    }
    return 0;
    }