#include <bits/stdc++.h>
using namespace std;
#define pb push_back
const int N = 3e6 + 10; // cooked
vector<int> g[N];
bitset<N> ex, vis;
int n, m;
int H(int x, int y, bool b) {
return (m + 1) * x + y + b * (N / 2);
}
int sz = 0;
void dfs(int s) {
vis[s] = 1, sz++;
for (auto u : g[s]) {
if (vis[u]) continue;
dfs(u);
}
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
ex.reset(); vis.reset();
for (int i = 1; i < N; ++i) g[i].clear();
cin >> n >> m;
char a[n+1][m+1];
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= m; ++j) {
cin >> a[i][j];
}
}
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= m; ++j) {
ex[H(i, j, 0)] = (j >= 3 && a[i][j] == 'W' && a[i][j-1] == 'G' && a[i][j-2] == 'R');
ex[H(i, j, 1)] = (i >= 3 && a[i][j] == 'W' && a[i-1][j] == 'G' && a[i-2][j] == 'R');
}
}
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= m; ++j) {
if (ex[H(i, j, 0)]) {
for (int t = 0; t <= 2; ++t) {
if (i <= n-t && ex[H(i+t, j-t, 1)]) g[H(i, j, 0)].pb(H(i+t, j-t, 1));
}
}
if (ex[H(i, j, 1)]) {
for (int t = 0; t <= 2; ++t) {
if (j <= n-t && ex[H(i-t, j+t, 0)]) g[H(i, j, 1)].pb(H(i-t, j+t, 0));
}
}
}
}
int ans = 0;
for (int i = 1; i < N; ++i) {
if (ex[i] && !vis[i]) {
sz = 0;
dfs(i);
ans += (sz+1)/2;
}
}
cout << ans << '\n';
}
