#include<bits/stdc++.h>
using namespace std;
inline void chmax(int &a, int b)
{
a = max(a, b);
}
int a[3005][3005];
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
int n, m; cin>>n>>m;
for(int i = 1; i <= n; i++){
for(int j = 1; j <= m; j++){
char x; cin>>x;
if(x == 'R') a[i][j] = 1;
if(x == 'G') a[i][j] = 2;
if(x == 'W') a[i][j] = 3;
}
}
int ans = 0;
for(int s = 2; s <= n+m; s++){
vector<int> state;
for(int i = 1; i <= n; i++) if(s-i >= 1 && s-i <= m){
int r = i, c = s-i, cur = 0;
if(a[r][c] == 1 && a[r][c+1] == 2 && a[r][c+2] == 3) cur++;
if(a[r][c] == 1 && a[r+1][c] == 2 && a[r+2][c] == 3) cur += 2;
state.push_back(cur);
//cerr<<"A"<<cur<<endl;
}
vector<vector<int>> dp(4, vector<int>(state.size()+1));
for(int j = 0; j < state.size(); j++){
for(int i = 0; i < 4; i++){
int ns = (i << 1); if(ns >= 4) ns -= 4;
chmax(dp[ns][j+1], dp[i][j]);
if(state[j]%2 == 1 && i == 0) chmax(dp[ns][j+1], dp[i][j]+1);
if(state[j] >= 2) chmax(dp[ns+1][j+1], dp[i][j]+1);
}
}
int add = 0;
for(int i = 0; i < 4; i++) add = max(add, dp[i][state.size()]);
ans += add;
}
cout<<ans;
}
