#include <iostream>
#include <bits/stdc++.h>
using namespace std;
#define mp make_pair
#define pb push_back
typedef long long int llo;
#define a first
#define b second
#define endl "\n"
vector<pair<pair<int,int>,int>> adj[3001][3001][2];
int vis[3001][3001][2];
int dp[3001][3001][2][2];//1 take 0 not take
/*int dfs(int ii,int jj,int kk){
vis[ii][jj][kk]=1;
dp[ii][jj][kk][1]=1;
for(auto nn:adj[ii][jj][kk]){
int aa;
int bb;
int cc;
aa=nn.a.a;
bb=nn.a.b;
cc=nn.b;
if(vis[aa][bb][cc]==0){
dfs(aa,bb,cc);
dp[ii][jj][kk][0]+=dp[aa][bb][cc][1];
dp[ii][jj][kk][1]+=dp[aa][bb][cc][0];
}
}
dp[ii][jj][kk][1]=max(dp[ii][jj][kk][1],dp[ii][jj][kk][0]);
}*/
int main(){
ios_base::sync_with_stdio(false);
memset(vis,1,sizeof(vis));
cin.tie(NULL);
memset(dp,0,sizeof(dp));
int n,m;
char s;
cin>>n>>m;
int it[n][m];
for(int i=0;i<n;i++){
for(int j=0;j<m;j++){
cin>>s;
if(s=='R'){
it[i][j]=0;
}
else if(s=='G'){
it[i][j]=1;
}
else{
it[i][j]=2;
}
// cout<<it[i][j]<<" ";
}
// cout<<endl;
}
/*int st=0;
for(int i=0;i<n;i++){
for(int j=0;j<m-2;j++){
if(it[i][j]==0 and it[i][j+1]==1 and it[i][j+2]==2){
vis[i][j][1]=0;
// cout<<i<<" "<<j<<" "<<1<<endl;
}
}
}
for(int i=0;i<n-2;i++){
for(int j=0;j<m;j++){
if(it[i][j]==0 and it[i+1][j]==1 and it[i+2][j]==2){
vis[i][j][0]=0;
//cout<<i<<" "<<j<<" "<<0<<endl;
if(j<m-2){
if(it[i][j+1]==1 and it[i][j+2]==2){
adj[i][j][0].pb(mp(mp(i,j),1));
adj[i][j][1].pb(mp(mp(i,j),0));
}
}
if(j<m-1 and j>0){
if(it[i+1][j-1]==0 and it[i+1][j+1]==2){
adj[i][j][0].pb(mp(mp(i+1,j-1),1));
adj[i+1][j-1][1].pb(mp(mp(i,j),0));
}
}
if(j>1){
if(it[i+2][j-2]==0 and it[i+2][j-1]==1){
adj[i][j][0].pb(mp(mp(i+2,j-2),1));
adj[i+2][j-2][1].pb(mp(mp(i,j),0));
}
}
}
}
}
int ans=0;
for(int i=0;i<n;i++){
for(int j=0;j<m;j++){
if(vis[i][j][0]==0){
dfs(i,j,0);
ans+=dp[i][j][0][1];
}
if(vis[i][j][1]==0){
dfs(i,j,1);
ans+=dp[i][j][1][1];
}
}
}
cout<<ans<<endl;
*/
return 0;
}
