// #pragma GCC optimize("O3,Ofast,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
using namespace std;
#define lli long long int
#define MP make_pair
#define pb push_back
#define REP(i,n) for(int i = 0; (i) < (n); (i)++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
void fastio() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
}
const double EPS = 0.00001;
const int INF = 1e9+500;
const int N = 3e3+5;
const int ALPH = 26;
const int LGN = 25;
constexpr int MOD = 1e9+7;
int n,m,q;
vector<string> a(N);
vector<vector<int> > vis(N, vector<int>(N, 0));
int ans = 0;
inline void solve() {
cin>>n>>m;
for(int i = 1; i<=n; i++) {
cin>>a[i];
a[i] = '0' + a[i];
}
for(int i = 1; i<=n; i++) {
for(int j = 1; j<=m; j++) {
if(a[i][j] != 'W') continue;
if(i > 2 && a[i - 1][j] == 'G' && a[i - 2][j] == 'R' && !vis[i - 1][j] && !vis[i - 2][j]) {
ans++;
vis[i - 1][j] = 1; vis[i - 2][j] = 1;
}
else if(j > 2 && a[i][j - 1] == 'G' && a[i][j - 2] == 'R' && !vis[i][j - 1] && !vis[i][j - 2] ){
ans++;
vis[i][j - 1] = 1; vis[i][j - 2] = 1;
}
}
}
cout << ans << "\n";
}
signed main() {
//fastio();
int test = 1;
//cin>>test;
while(test--) {
solve();
}
}
