#include <iostream>
#include <vector>
using namespace std;
int main()
{
int n,m;
cin >> n >> m;
int wyn=0;
vector<string> v(n+2);
for (int64_t i=0; i<m+2; i++) v[0]+='#';
for (int64_t i=1; i<n+1; i++){
v[i]+='#';
string akt;
cin >> akt;
v[i]+=akt;
v[i]+='#';
}
for (int64_t i=0; i<m+2; i++) v[n+1]+='#';
//for (auto it:v) cout << it << '\n';
//cout << '\n';
for (int i=1; i<n+1; i++){
for (int j=1; j<m+1; j++){
//cout << i << ' ' << j << '\n';
if (v[i][j]=='G' and v[i][j-1]=='R' and v[i][j+1]=='W'){
if (v[i][j]=='G' and v[i-1][j]=='R' and v[i+1][j]=='W'){
v[i][j]=v[i][j+1]=v[i+1][j]='#';
wyn++;
//cout << i << ' ' << j << '\n';
}
else{
//cout << i << ' ' << j << '\n';
v[i][j]=v[i][j+1]=v[i][j-1]='#';
wyn++;
//cout << i << ' ' << j << '\n';
}
}
else if (v[i][j]=='G' and v[i-1][j]=='R' and v[i+1][j]=='W'){
//cout << i << ' ' << j << '\n';
v[i][j]=v[i-1][j]=v[i+1][j]='#';
wyn++;
//cout << i << ' ' << j << '\n';
}
}
}
cout << wyn;
return 0;
}
