#include <bits/stdc++.h>
using namespace std;
#define int long long
#define OYY LLONG_MAX
#define faster ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define fi first
#define se second
#define FOR for(int i=1;i<=n;i++)
#define pb push_back
#define lim 3005
int n,m,cev,maxi,cur1,cur2;
char dizi[lim][lim];
int vis[lim][lim][2],dp[lim][lim][2];
vector<pair<int,int>> sol,ust;
inline int ind(int x,int y,int z){
return n*m*z+(x-1)*m+y;
}
inline bool check(int x,int y){
return x>=1 && x<=n && y>=1 && y<=m;
}
inline bool check_left(int x,int y){
return check(x,y) && check(x,y+1) && check(x,y+2) && dizi[x][y]=='R' && dizi[x][y+1]=='G' && dizi[x][y+2]=='W';
}
inline bool check_top(int x,int y){
return check(x,y) && check(x+1,y) && check(x+2,y) && dizi[x][y]=='R' && dizi[x+1][y]=='G' && dizi[x+2][y]=='W';
}
inline int f(int pl,int pu,int kim){
if(~dp[pl][pu][kim])return dp[pl][pu][kim];
int cur=0;
if(kim){
for(int i=pl;i<sol.size();i++){
if(sol[i].fi<=ust[pu].fi+2)continue;
cur=max(cur,f(i,pu,0)+1);
break;
}
if(pu+1<ust.size())cur=max(cur,f(pl,pu+1,1)+1);
}
else{
for(int i=pu;i<ust.size();i++){
if(ust[i].fi<=sol[pl].fi)continue;
cur=max(cur,f(pl,i,1)+1);
}
if(pl+1<sol.size())cur=max(cur,f(pl+1,pu,0)+1);
}
return dp[pl][pu][kim]=cur;
}
int32_t main(){
faster
cin>>n>>m;
FOR{
string s;cin>>s;
for(int j=0;j<m;j++){
dizi[i][j+1]=s[j];
}
}
FOR{
for(int j=1;j<=m;j++){
if(vis[i][j][0] || vis[i][j][1])continue;
sol.clear();
ust.clear();
queue<pair<int,pair<int,int>>> q;
if(check_left(i,j)){
q.push({i,{j,0}});
}
if(check_top(i,j)){
q.push({i,{j,1}});
}
while(q.size()){
int l=q.front().fi,r=q.front().se.fi,kim=q.front().se.se;
q.pop();
if(vis[l][r][kim])continue;
vis[l][r][kim]=1;
if(kim){
if(check_left(l,r))q.push({l,{r,0}});
if(check_left(l+1,r-1))q.push({l+1,{r-1,0}});
if(check_left(l+2,r-2))q.push({l+2,{r-2,0}});
ust.pb({l,r});
}
else{
if(check_top(l,r))q.push({l,{r,1}});
sol.pb({l,r});
}
}
//~ reverse(sol.begin(),sol.end());
//~ reverse(ust.begin(),ust.end());
//~ cout<<i<<" -> "<<j<<endl;
//~ for(auto a:sol)cout<<a.fi<<" "<<a.se<<endl;
//~ cout<<endl;
//~ for(auto a:ust)cout<<a.fi<<" "<<a.se<<endl;
//~ cout<<endl;
for(int i=0;i<sol.size();i++){
for(int j=0;j<ust.size();j++){
dp[i][j][0]=dp[i][j][1]=-1;
}
}
int cur_ans=0;
if(sol.size())cur_ans=max(cur_ans,f(0,0,0)+1);
//cout<<cur_ans<<endl;
if(ust.size())cur_ans=max(cur_ans,f(0,0,1)+1);
// cout<<cur_ans<<endl;
cev+=cur_ans;
for(int i=0;i<sol.size();i++){
for(int j=0;j<ust.size();j++){
dp[i][j][0]=dp[i][j][1]=-1;
}
}
}
}
cout<<cev<<'\n';
return 0;
}
/*
*
*
RRRR
RRGW
RGWR
RGWW
*/
