#include <bits/stdc++.h>
#define pb push_back
using namespace std;
const int MAXN = 3000;
const int MAXM = 3000*3000;
int n, m;
string mp[MAXN+1], ss;
int p[MAXN+1][MAXN+1];
int a, b;
int ans;
vector <vector<int>> pathA, pathB;
vector <int> degB;
vector <bool> visA, visB;
void DFS(int now) {
for (int i : pathB[now]) {
if (visA[i]) continue;
visA[i] = 1;
ans--;
for (int j : pathA[i]) {
if (visB[j]) continue;
degB[j]--;
if (degB[j] == 1) {
degB[j]--;
visB[j] = 1;
DFS(j);
}
}
}
}
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0);
cin >> n >> m;
for (int i = 1; i <= n; i++) {
cin >> ss;
mp[i] = ' ' + ss;
}
pathA.pb(vector<int>());
pathB.pb(vector<int>());
degB.pb(0);
visA.pb(0);
visB.pb(0);
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
if (i >= 3 && mp[i][j] == 'W' && mp[i-1][j] == 'G' && mp[i-2][j] == 'R') {
a++;
pathA.pb(vector<int>());
visA.pb(0);
p[i][j] = p[i-1][j] = p[i-2][j] = a;
}
}
}
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
if (j >= 3 && mp[i][j] == 'W' && mp[i][j-1] == 'G' && mp[i][j-2] == 'R') {
b++, pathB.pb(vector<int>());
degB.pb(0);
visB.pb(0);
if (p[i][j]) {
pathB[b].pb(p[i][j]);
degB[b]++;
pathA[p[i][j]].pb(b);
}
if (p[i][j-1]) {
pathB[b].pb(p[i][j-1]);
degB[b]++;
pathA[p[i][j-1]].pb(b);
}
if (p[i][j-2]) {
pathB[b].pb(p[i][j-2]);
degB[b]++;
pathA[p[i][j-2]].pb(b);
}
}
}
}
ans = a+b;
for (int i = 1; i <= b; i++) {
if (degB[i] == 1 && !visB[i]) {
visB[i] = 1;
degB[i]--;
DFS(i);
}
}
for (int i = 1; i <= b; i++) {
if (degB[i] > 1) ans--;
}
cout << ans << "\n";
return 0;
}
