#include<bits/stdc++.h>
using namespace std;
#define int long long
#define fi first
#define se second
#define pb push_back
#define mp make_pair
typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<ii, ii> iiii;
const int N = 3e3 + 5;
const int oo = 1e18 + 7, mod = 1e9 + 7;
int n, m;
char c[N][N];
int dp[2 * N][3][3];
bool ck(int x, int y, int dir){
if(dir == 2) return 0;
if(!dir){
if(y >= (m - 1)) return 0;
return (c[x][y] == 'R' && c[x][y + 1] == 'G' && c[x][y + 2] == 'W');
}
else{
if(x >= (n - 1)) return 0;
return (c[x][y] == 'R' && c[x + 1][y] == 'G' && c[x + 2][y] == 'W');
}
}
void process(){
cin >> n >> m;
for(int i = 1; i <= n; i++){
for(int j = 1; j <= m; j++) cin >> c[i][j];
}
int answer = 0;
for(int i = 2; i <= (n + m); i++){
int sta = max(i - m, 1LL), en = min(n, i - 1);
for(int j = sta; j <= en; j++){
for(int k = 0; k < 3; k++){
for(int h = 0; h < 3; h++) dp[j][k][h] = -oo;
}
}
dp[sta][2][0] = 0;
dp[sta][0][0] = ck(sta, i - sta, 0);
dp[sta][1][0] = ck(sta, i - sta, 1);
for(int j = sta; j < en; j++){
for(int k = 0; k <= 2; k++){
for(int h = 0; h <= 2; h++){
for(int nxt = 0; nxt <= 2; nxt++){
if(nxt == 0){
if(k == 1 || h == 1) continue;
}
dp[j + 1][nxt][k] = max(dp[j + 1][nxt][k], dp[j][k][h] + ck(j + 1, i - (j + 1), nxt));
}
}
}
}
int temp = -1;
for(int i = 0; i <= 2; i++){
for(int j = 0; j <= 2; j++) temp = max(temp, dp[en][i][j]);
}
//cout << i << " " << temp << "\n";
answer += temp;
}
cout << answer << "\n";
}
signed main(){
ios_base::sync_with_stdio(0);
int t = 1;
//cin >> t;
while(t--) process();
}
