//#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
//using namespace atcoder;
using ll = long long;
#define all(A) A.begin(),A.end()
using vll = vector<ll>;
#define rep(i, n) for (long long i = 0; i < (long long)(n); i++)
using Graph = vector<vector<ll>>;
Graph G;
vll dist;
vector<bool> seen;
ll mod = 1e9 + 7;

ll inv(ll N) {
    ll a = N, b = mod, c = 1, d = 0;
    while (b > 0) {
        ll t = a / b;
        a -= t * b;
        swap(a, b);
        c -= t * d;
        swap(c, d);

    }
    c %= mod;
    if (c < 0)c += mod;
    return c;

}

int main() {
    ll N,M;
    cin>>N>>M;
    ll an=N*M;
    rep(i,N){
        string S;
        cin>>S;
        rep(j,M){
            an-=(S[j]=='W');
        }
    }
    cout<<an<<endl;
}