#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define INF 100000000000000000
//#define int long long
#define lchild(i) (i*2 + 1)
#define rchild(i) (i*2 + 2)
#define mid(l, u) ((l+u)/2)
#define x(p) p.first
#define y(p) p.second
#define MOD 998244353
#define ordered_set tree<pair<int, int>, null_type,less<pair<int, int>>, rb_tree_tag,tree_order_statistics_node_update>
using namespace std;
struct node{
char c;
int first, second;
};
int n, m;
const int N = 3000;//first->horizontal, second -> vertical
vector<bool> vis;
int currnode = 0;
node mat[N][N];
vector<pair<int, int>> nv;
int solve(int i){
int type = 1;
if(mat[nv[i].first][nv[i].second].first != i){
type = 0;
}
//cout<<i<<" "<<type<<endl;
vector<int> lvls;
queue<pair<pair<int, int>, int>> q;
q.push({{i, type}, 0});
vis[i] = true;
while(!q.empty()){
pair<pair<int, int>, int> curr = q.front();
q.pop();
if(lvls.size()<=curr.second) lvls.push_back(1);
else lvls[curr.second]++;
if(curr.first.second == 0){
int i = nv[curr.first.first].first;
int j = nv[curr.first.first].second;
if(mat[i][j].first != -1){
if(!vis[mat[i][j].first]){
vis[mat[i][j].first] = true;
q.push({{mat[i][j].first, 1}, curr.second+1});
}
}
if(j>0 && mat[i+1][j-1].first!=-1){
if(!vis[mat[i+1][j-1].first]){
vis[mat[i+1][j-1].first] = true;
q.push({{mat[i+1][j-1].first, 1}, curr.second+1});
}
}
if(j>1 && mat[i+2][j-2].first!=-1){
if(!vis[mat[i+2][j-2].first]){
vis[mat[i+2][j-2].first] = true;
q.push({{mat[i+2][j-2].first, 1}, curr.second+1});
}
}
}
else{
int i = nv[curr.first.first].first;
int j = nv[curr.first.first].second;
if(mat[i][j].second != -1){
if(!vis[mat[i][j].second]){
vis[mat[i][j].second] = true;
q.push({{mat[i][j].second, 0}, curr.second+1});
}
}
if(i>0 && mat[i-1][j+1].second!=-1){
if(!vis[mat[i-1][j+1].second]){
vis[mat[i-1][j+1].second] = true;
q.push({{mat[i-1][j+1].second, 0}, curr.second+1});
}
}
if(i>1 && mat[i-2][j+2].second!=-1){
if(!vis[mat[i-2][j+2].second]){
vis[mat[i-2][j+2].second] = true;
q.push({{mat[i-2][j+2].second, 0}, curr.second+1});
}
}
}
}
if(lvls.size()==1) return lvls[0];
if(lvls.size()==2) return max(lvls[0], lvls[1]);
pair<int, int> dp = {lvls[0], lvls[1]};
int tr = max(dp.first, dp.second);
for(int i = 2;i<lvls.size();i++){
int temp = max(dp.first + lvls[i], dp.second);
dp.first = dp.second;
dp.second = temp;
tr = max(tr, temp);
}
return tr;
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin>>n>>m;
for(int i = 0;i<n;i++){
string s;
for(int j = 0;j<m;j++) cin>>mat[i][j].c;
}
for(int i = 0;i<n;i++){
for(int j = 0;j<m;j++) mat[i][j].first = mat[i][j].second = -1;
}
for(int i = 0;i<n;i++){
for(int j = 0;j<m;j++){
if(mat[i][j].c!='R') continue;
if(i+2<n){
if(mat[i+1][j].c=='G' && mat[i+2][j].c=='W'){
int cnode = currnode++;
vis.push_back(false);
nv.push_back({i, j});
mat[i][j].second = cnode;
}
}
if(j+2<m){
if(mat[i][j+1].c=='G' && mat[i][j+2].c=='W'){
int cnode = currnode++;
vis.push_back(false);
nv.push_back({i, j});
mat[i][j].first = cnode;
}
}
}
}
int ans = 0;
for(int i = 0;i<currnode;i++){
/*cout<<i<<" is connected to: ";
for(int j: adj[i]){
cout<<j<<" ";
}
cout<<endl;
*/
if(!vis[i]){
ans+=solve(i);
}
}
cout<<ans<<endl;
//create a node out of each skewer that you can make
//connect nodes that intersect with each other
//For each connected component,
}
/*
4 4
RGWR
GRRG
WGGW
WWWR
5 5
RGRGW
GRRGW
WGGWR
RWRGW
RGWGW
*/
