#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cmath>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <bitset>
#include <numeric>
#include <functional>
#include <iomanip>
#include <sstream>
#define int long long
#define pb push_back
#define b begin()
#define e end()
#define fi first
#define se second
#define makep make_pair
using namespace std;
int mod=1e9+7;
void ai(vector<int> &v){
for(auto &go : v){
cin>>go;
}
}
void yesno(int k){
if(k==1){
cout<<"Yes";
}
else{
cout<<"No";
}
}
pair<int,int> dfs(int node,vector<vector<int>> &adj,vector<int> &viss, int ayrac,int l,int r){
viss[node]=1;
if(node<ayrac){
l++;
}
else{
r++;
}
for(auto go:adj[node]){
if(viss[go]==0){
dfs(go,adj,viss,ayrac,l,r);
}
}
return {l,r};
}
void solve(){
int n,m;
cin>>n>>m;
vector<vector<char>> arr(n,vector<char>(m));
vector<vector<int>> vis(n,vector<int>(m));
for(int i=0;i<n;i++){
for(int j=0;j<m;j++){
cin>>arr[i][j];
}
}
int cevap=0;
int vissayac=1;
for(int i=0;i<n;i++){
for(int j=0;j<m-2;j++){
if(arr[i][j]=='R'&&arr[i][j+1]=='G'&&arr[i][j+2]=='W'){
cevap++;
vis[i][j]=vissayac;
vissayac++;
//cout<<"SS"<<i<<" "<<j<<endl;
}
}
}
vector<vector<int>> adj(n*n);
int ayrac=vissayac;
for(int j=0;j<m;j++){
for(int i=0;i<n-2;i++){
if(arr[i][j]=='R'&&arr[i+1][j]=='G'&&arr[i+2][j]=='W'){
if(vis[i][j]==0&&vis[i+1][j]==0&&vis[i+2][j]==0){
cevap++;
}
int k=0;
if(vis[i][j]!=0){
adj[vis[i][j]].pb(vissayac);
adj[vissayac].pb(vis[i][j]);
k=1;
}
if(vis[i+1][j]!=0){
adj[vis[i+1][j]].pb(vissayac);
adj[vissayac].pb(vis[i+1][j]);
k=1;
}
if(vis[i+2][j]!=0){
adj[vis[i+2][j]].pb(vissayac);
adj[vissayac].pb(vis[i+2][j]);
k=1;
}
vissayac+=k;
//cout<<"YA"<<i<<" "<<j<<endl;
}
}
}
vector<int> viss(vissayac,0);
for(int i=1;i<ayrac;i++){
if(viss[i]==0){
pair<int,int> mima=dfs(i,adj,viss,ayrac,0,0);
if(mima.first<mima.second){
cevap-=mima.first;
cevap+=mima.second;
}
}
}
cout<<cevap;
}
signed main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
int t=1;
//cin>>t;
while(t--){
solve();
}
}
