/*
 * CTGAME.cpp
 *
 *  Created on: Jun 11, 2014
 *      Author: Arpit Bhayani
 */

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

using namespace std;

#define DEBUG 0
#define gc getchar
#define ll long long

void scanint(ll int &x) {
    register ll int c = gc();
    x = 0;
    for (; (c < 48 || c > 57); c = gc())
        ;
    for (; c > 47 && c < 58; c = gc()) {
        x = (x << 1) + (x << 3) + c - 48;
    }
}

int readline(char * str) {

    int i = 0;
    char ch;
    while ((ch = getchar()) != '\n') {
        str[i++] = ch;
    }
    str[i] = '\0';
    return i;
}

int array[1001][1001];

int maxarea(int * hist, int n) {

    /*printf("HISTOGRAM : ");
     for ( int j = 0 ; j < n ; j++ ) {
     printf("%d " , hist[j]);
     }
     printf("\n");*/

    stack<int> s;
    int maxarea = 0, tp, area, i = 0;
    while (i < n) {
        if (s.empty() || hist[s.top()] <= hist[i]) {
            s.push(i++);
        } else {
            tp = s.top();
            s.pop();
            area = hist[tp] * (s.empty() ? i : i - s.top() - 1);
            if (area > maxarea)
                maxarea = area;
        }
    }

    while (!s.empty()) {
        tp = s.top();
        s.pop();
        area = hist[tp] * (s.empty() ? i : i - s.top() - 1);
        if (area > maxarea)
            maxarea = area;
    }

    return maxarea;
}

int main(int argc, char * argv[]) {

    int t;
    scanf("%d", &t);
    while (t--) {
        char ch;
        int n, m;
        scanf("%d%d", &n, &m);

        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                cin >> ch;
                if (ch == 'R') {
                    array[i][j] = 0;
                } else {
                    array[i][j] = 1;
                }
            }
        }

        for (int i = 1; i < n; i++) {
            for (int j = 0; j < m; j++) {
                if (array[i][j] == 1)
                    array[i][j] += array[i - 1][j];
            }
        }

        int maxa = 0;
        for (int i = 0; i < n; i++) {
            int temp = maxarea(array[i], m);
            if (temp > maxa)
                maxa = temp;
        }

        printf("%lld\n", (ll int) maxa * 3LL);

    }
    return 0;
}