#include <bits/stdc++.h>
#define PI acos(-1.0)
#define mem(a,b) memset((a),b,sizeof(a))
#define TS printf("!!!\n")
#define pb push_back
//std::ios::sync_with_stdio(false);
using namespace std;
//priority_queue<int,vector<int>,greater<int>> que;
const double EPS = 1.0e-8;
typedef pair<int, int> pairint;
typedef long long ll;
typedef unsigned long long ull;
const int maxn = 2e5 + 100;
const int maxm = 300;
//next_permutation
//priority_queue<int, vector<int>, greater<int>> que;
int n, m;
int num[1005][1005];
int r[1005][1005], l[1005][1005];
void pf()
{
cout<<endl;
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= m; j++)
{
cout << num[i][j] << " ";
}
cout << endl;
}
cout<<endl;
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= m; j++)
{
cout << l[i][j] << " ";
}
cout << endl;
}
cout<<endl;
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= m; j++)
{
cout << r[i][j] << " ";
}
cout << endl;
}
}
char a[10];
int main()
{
//freopen("bonuses.in", "r", stdin);
//freopen("out.txt", "w", stdout);
int t;
cin >> t;
while (t--)
{
int ans = 0;
cin >> n >> m;
for (int i = 1; i <= n; i++)
for (int j = 1; j <= m; j++)
{
scanf("%s", a);
num[i][j] = a[0] == 'R' ? 0 : (num[i - 1][j] + 1);
}
//pf();
int lenr, lenc;
for (int i = 1; i <= n; i++)
for (int j = 1; j <= m; j++)
{
l[i][j] = r[i][j] = j;
}
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= m; j++)
{
int cur = j;
while (cur != 1 && num[i][cur-1] >= num[i][j])
{
cur = l[i][cur - 1];
}
l[i][j] = cur;
}
for (int j = m; j >= 1; j--)
{
int cnt = j;
while (cnt != m && num[i][cnt+1] >= num[i][j])
{
cnt = r[i][cnt + 1];
}
r[i][j] = cnt;
}
for(int j=1;j<=m;j++)
ans = max(ans, (r[i][j] - l[i][j] + 1) * num[i][j] * 3);
}
//pf();
cout << ans << endl;
}
}