#include <bits/stdc++.h>
#define pb push_back
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " : " << x << '\n'
using namespace std;
typedef long long ll;
typedef long double ld;
typedef string str;
typedef pair<ll, ll> pll;
const ll Mod = 1000000007LL;
const int N = 3e3 + 10;
const ll Inf = 2242545357980376863LL;
const ll Log = 30;
ll n, m;
str s[N];
int Right(int i, int j){
if(j + 2 >= m) return false;
return (s[i][j] == 'R') && (s[i][j + 1] == 'G') && (s[i][j + 2] == 'W');
}
int Down(int i, int j){
if(i + 2 >= n) return false;
return (s[i][j] == 'R') && (s[i + 1][j] == 'G') && (s[i + 2][j] == 'W');
}
vector<int> V[N + N];
int dp[N][4];
int main(){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> m;
for(int i = 0; i < n; i++) cin >> s[i];
for(int i = 0; i < n + m - 1; i++) V[i].pb(0);
for(int i = 0; i < n; i++){
for(int j = 0; j < m; j++){
V[i + j].pb(Right(i, j) * 2 + Down(i, j));
}
}
ll ans = 0;
int k;
for(int i = 0; i < n + m - 1; i++){
k = V[i].size();
for(int i = 0; i < k; i++) fill(dp[i], dp[i] + 4, -Inf);
dp[0][0] = 0;
for(int j = 1; j < k; j++){
for(int mk = 0; mk < 4; mk++){
dp[j][(mk << 1) & 3] = max(dp[j][(mk << 1) & 3], dp[j - 1][mk]);
}
if(V[i][j] & 1){
for(int mk = 0; mk < 4; mk++){
dp[j][(mk << 1 | 1 ) & 3] = max(dp[j][(mk << 1 | 1 ) & 3], dp[j - 1][mk] + 1);
}
}
if(V[i][j] & 2){
dp[j][0] = max(dp[j][0], dp[j - 1][0] + 1);
}
}
ans += *max_element(dp[k - 1], dp[k - 1] + 4);
}
cout << ans << '\n';
return 0;
}
