#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
void solve(){
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
ll n,m;
ll toplam=0;
cin>>n>>m;
string s1,s2,s3;
if(n<3 && m>=3){
for(int j=0;j<n;j++){
cin>>s1;
for(int i=0;i<m-2;i++){
if(s1[i]=='R' && s1[i+1]=='G' && s1[i+2]=='W'){
toplam++;
s1[i]='c';
s1[i+1]='c';
s1[i+2]='c';
}
}
}
cout<<toplam;
return 0;
}
if(n<3 && m<3){
cout<<"0";
return 0;
}
cin>>s1>>s2>>s3;
for(int i=0;i<m;i++){
if((i<m-2) && (s1[i]=='R') && (s1[i+1]=='G') && (s1[i+2]=='W')){
toplam++;
s1[i]='c';
s1[i+1]='c';
s1[i+2]='c';
}
if((s1[i]=='R') && (s2[i]=='G') && (s3[i]=='W') ){
toplam++;
s1[i]='c';
s2[i]='c';
s3[i]='c';
}
}
for(int j=1;j<n;j++){
if(j<n-2){
string s2_2=s2;
s2=s3;
s1=s2_2;
cin>>s3;
}
else{
s1=s2;
s2=s3;
}
for(int i=0;i<m;i++){
if((i<m-2) && (s1[i]=='R') && (s1[i+1]=='G') && (s1[i+2]=='W')){
toplam++;
s1[i]='c';
s1[i+1]='c';
s1[i+2]='c';
}
if((j<n-2) && (s1[i]=='R') && (s2[i]=='G') && (s3[i]=='W') ){
toplam++;
s1[i]='c';
s2[i]='c';
s3[i]='c';
}
}
}
cout<<toplam;
}
