#include<bits/stdc++.h>
using namespace std;
string s[3005];
vector<int>adj[18000005];
int n,m;
int can[3005][3005];
int can2[3005][3005];
int pp[18000005];
int g(int x,int y){
return x*m+y;
}
int val[5],vis[18000005];
void dfs(int u,int par){
val[par]++;
pp[u]=par;
for(auto x:adj[u]){
if(vis[x]){
assert((pp[u]==(pp[x]^1)));
continue;
}
vis[x]=1;
dfs(x,par^1);
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cin>>n>>m;
for(int i=0;i<n;i++){
cin>>s[i];
}
for(int i=0;i<n;i++){
for(int j=0;j<m;j++){
if(j+2<m){
if(s[i][j]=='R'&&s[i][j+1]=='G'&&s[i][j+2]=='W'){
can[i][j]=1;
if(i+2<n&&s[i+1][j]=='G'&&s[i+2][j]=='W')adj[g(i,j)].push_back(n*m+g(i,j)),adj[n*m+g(i,j)].push_back(g(i,j));
if(i+1<n&&i-1>=0&&s[i-1][j+1]=='R'&&s[i+1][j+1]=='W')adj[g(i,j)].push_back(n*m+g(i-1,j+1)),adj[n*m+g(i-1,j+1)].push_back(g(i,j));
if(i-2>=0&&s[i-2][j+2]=='R'&&s[i-1][j+2]=='G')adj[g(i,j)].push_back(n*m+g(i-2,j+2)),adj[n*m+g(i-2,j+2)].push_back(g(i,j));
}
}
}
}
for(int i=0;i<n;i++){
for(int j=0;j<m;j++){
if(i+2<n){
if(s[i][j]=='R'&&s[i+1][j]=='G'&&s[i+2][j]=='W'){
can2[i][j]=1;
}
}
}
}
int ans=0;
for(int i=0;i<n;i++)for(int j=0;j<m;j++){
if(!vis[g(i,j)]&&can[i][j]){
val[0]=val[1]=0;
vis[g(i,j)]=1;
dfs(g(i,j),0);
ans+=max(val[0],val[1]);
}
if(!vis[g(i,j)+n*m]&&can2[i][j]){
val[0]=val[1]=0;
vis[g(i,j)+n*m]=1;
dfs(g(i,j)+n*m,0);
ans+=max(val[0],val[1]);
}
}
cout<<ans<<"\n";
}
