#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pll pair<int, int>
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define endl '\n'
#define ld long double
signed main(){
int h,w;cin>>h>>w;
vector<vector<int>> m(h+2, vector<int>(w+2, 1));
for(int i=1;i<=h;i++){
for(int j=1;j<=w;j++){
char c;cin>>c;
if(c=='R')m[i][j]=0;
else if(c=='G')m[i][j]=1;
else m[i][j]=2;
}
}
int ans=0;
vector<int> layer(h+w, 0);
for(int l=2;l<h+w;l++){
vector<array<int,3>> dp(w+2, {0, 0, 0});
for(int y=(l>h+1?l-h:1);y<=w;y++){
int x=l-y;
if(x <= 0)break;
//~ cout<<x<<" "<<y<<endl;
if(m[x][y-1]==0 and m[x][y]==1 and m[x][y+1]==2){
dp[x][1]=max({dp[x+1][0], dp[x+1][1]})+1;
}
if(m[x-1][y]==0 and m[x][y]==1 and m[x+1][y]==2){
dp[x][2]=max({dp[x+1][0], dp[x+1][2]})+1;
}
dp[x][0]=max({dp[x+1][0],dp[x+1][1], dp[x+1][2]});
layer[l]=max({layer[l], dp[x][0],dp[x][1],dp[x][2]});
}
ans+=layer[l];
//~ printf("layer %lld, cont %lld\n", l, layer[l]);
}
cout<<ans;
}
