#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;
const int N = 1e3 + 5;

char arr[N][N];
int n, m, height[N][N];
int lef[N], rig[N];

int func(int row)
{
    height[row][0] = height[row][m+1] = -1;
    vector<int> temp;
    temp.push_back(0);
    for (int i = 1; i <= m; ++i)
    {
        while (height[row][temp.back()] >= height[row][i]) temp.pop_back();
        lef[i] = temp.back();
        temp.push_back(i);
    }
    temp.clear();
    temp.push_back(m+1);
    for (int i = m; i >= 1; --i)
    {
        while (height[row][temp.back()] >= height[row][i]) temp.pop_back();
        rig[i] = temp.back();
        temp.push_back(i);
    }

    int res = 0;
    for (int i = 1; i <= m; ++i) res = max(res, height[row][i]*(rig[i]-lef[i]-1));
    return res;
}

int main()
{
    scanf("%d %d", &n, &m);
    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= m; ++j)
        {
            cin >> arr[i][j];
            if (arr[i][j] == 'F') height[i][j] = height[i-1][j] + 1;
//          cout << height[i][j] << " ";
        }   
//      cout << endl;
    }   

    int res = 0;
    for (int i = 1; i <= n; ++i)
    {
        res = max(res, func(i));
    }
    printf("%d", res*3);
    return 0;
}