#include<bits/stdc++.h>
using namespace std;
#define f first
#define s second
typedef long long ll;
typedef long double ld;
typedef pair<int, pair<int, int>> ft;
const ld PI = acos(-1);
const int maxn = 3e3+5;
const ll inf = 1e18;
const int mod = 998244353;
int n, m;
ll ans = 0, mx = -inf;
char board[maxn][maxn];
int dp[maxn][maxn][4];
int st[maxn][maxn];
signed main(){
ios::sync_with_stdio(false);
cin.tie(0);
cin >> n >> m;
for(int i = 1; i <= n; i++){
for(int j = 1; j <= m; j++)cin >> board[i][j];
}
int ans = 0;
for(int i = 1; i <= n; i++){
for(int j = 1; j <= m; j++){
if(j+2 <= m && board[i][j] == 'R' && board[i][j+1] == 'G' && board[i][j+2] == 'W'){
st[i][j]^=1;
}
if(i+2 <= n && board[i][j] == 'R' && board[i+1][j] == 'G' && board[i+2][j] == 'W'){
st[i][j]^=2;
}
}
}
for(int i = n; i >= 1; i--){
for(int j = 1; j <= m; j++){
for(int k = 0; k < 3; k++){
dp[i][j][k] = dp[i+1][j-1][k+1];
}
dp[i][j][0] = dp[i+1][j-1][0];
if(st[i][j]&2)dp[i][j][0] = max(dp[i][j][0], dp[i+1][j-1][0]+1);
if(st[i][j]&1){
for(int k = 0; k < 4; k++)dp[i][j][3] = max(dp[i][j][3], dp[i+1][j-1][k]+1);
}
/*for(int k = 0; k < 4; k++){
cout << i << " " << j << " " << k << " " << dp[i][j][k] << "\n";
}*/
if(i == 1 || j == m)ans += max({dp[i][j][0], dp[i][j][1], dp[i][j][2], dp[i][j][3]});
}
}
cout << ans;
}
