#include <iostream>
#include <algorithm>
#include <cmath>
#include <fstream>
#include <stack>
using namespace std;
using ll=long long;
using ld=long double;

const int maxn=1e6 +2;

ll n,m,h[1002],Max=-1,Left[10002],Right[10002];
char x[1002][1002];

ll calc()
{
    stack<ll> S;
    for(ll i = 1; i <= n; i++)
    {
        while(!S.empty() && h[S.top()] >= h[i])
        {
            S.pop();
        }
        Left[i] = S.empty() ? 0 : S.top();
        S.push(i);
    }
    while(!S.empty()) S.pop();
    for(ll i = n; i >= 1; i--)
    {
        while(!S.empty() && h[S.top()] >= h[i]) S.pop();
        Right[i] = S.empty() ? n + 1 : S.top();
        S.push(i);
    }
    ll res = 0;
    for(ll i=1;i<=n;i++)
    {
        ll temp = (ll) h[i] * (Right[i]-Left[i]-1);
        if(temp>res) res = temp;
    }
    return res;
}

int main()
{
    //freopen("MAXRECT.INP","r",stdin);
    //freopen("MAXRECT.OUT","w",stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    cin>>n>>m;
    for(ll i=1;i<=n;i++)
    {
        for(ll j=1;j<=m;j++)
        {
            cin>>x[i][j];
        }
    }
    for(ll i=1;i<=n;i++)
    {
        fill_n(h,1002,0);
        fill_n(Left,1002,0);
        fill_n(Right,1002,0);
        for(ll j=1;j<=i;j++)
        {
            for(ll u=1;u<=m;u++)
            {
                if(x[j][u]=='W') h[u]++;
                else h[u]=0;
            }
        }
        ll res1 = calc();
        Max = max(Max, res1);
    }
    cout << Max;

}