#include <bits/stdc++.h>
#define ii pair <int, int>
#define fi first.first
#define se first.second
#define th second
using namespace std;
const int O = 3e3 + 5;
const int base = 500;
const int mod = 998244353;
int n, m, cnt, cal, c[O][O];
bool dd[2][O][O];
string a[O];
vector <pair <ii, int>> g(pair <ii, int> u){
vector <pair <ii, int>> res;
int i = u.se;
int j = u.th;
if (u.fi == 0){
if (i > 2 && (c[i - 2][j + 2] & 2)){
res.push_back(make_pair(make_pair(1, i - 2), j + 2));
}
if (i > 1 && (c[i - 1][j + 1] & 2)){
res.push_back(make_pair(make_pair(1, i - 1), j + 1));
}
if (c[i][j] & 2){
res.push_back(make_pair(make_pair(1, i), j));
}
}
if (u.fi == 1){
if (j > 2 && (c[i + 2][j - 2] & 1)){
res.push_back(make_pair(make_pair(0, i + 2), j - 2));
}
if (j > 1 && (c[i + 1][j - 1] & 1)){
res.push_back(make_pair(make_pair(0, i + 1), j - 1));
}
if (c[i][j] & 1){
res.push_back(make_pair(make_pair(0, i), j));
}
}
return res;
}
int dfs(pair <ii, int> u){
vector <int> f[2], b;
queue <pair <ii, int>> q;
q.push(u);
int turn = u.fi;
dd[u.fi][u.se][u.th] = 1; cal = 0;
while (q.size()){
u = q.front(); q.pop();
//cout << u.fi << " " << u.se << " " << u.th << endl;
if (turn != u.fi) b.push_back(cal);
cal = turn == u.fi ? cal + 1 : 1;
turn = u.fi;
auto adj = g(u);
for (auto v : adj){
if (!dd[v.fi][v.se][v.th]){
dd[v.fi][v.se][v.th] = 1;
q.push(v);
}
}
}
b.push_back(cal);
int m = b.size() - 1;
f[0].resize(m + 1);
f[1].resize(m + 1); f[1][0] = b[0];
for (int i = 1; i <= m; ++ i){
f[1][i] = f[0][i - 1] + b[i];
f[0][i] = max(f[0][i - 1], f[1][i - 1]);
}
return max(f[0][m], f[1][m]);
}
main(){
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin >> n >> m;
for (int i = 1; i <= n; ++ i){
cin >> a[i]; a[i] = " " + a[i];
for (int j = 1; j <= m; ++ j){
if (a[i][j] == 'W' && j >= 3){
c[i][j - 2] += (a[i][j - 2] == 'R' && a[i][j - 1] == 'G');
}
if (a[i][j] == 'W' && i >= 3){
c[i - 2][j] += 2 * (a[i - 2][j] == 'R' && a[i - 1][j] == 'G');
}
}
}
int res = 0;
for (int i = 1; i <= n; ++ i){
for (int j = 1; j <= m; ++ j){
if (c[i][j] > 0){
cnt = cal = 0;
//cout << "debug " << i << " " << j << endl;
if ((c[i][j] & 1) && !dd[0][i][j]){
cnt = dfs(make_pair(make_pair(0, i), j));
}
if ((c[i][j] & 2) && !dd[1][i][j]){
cnt = dfs(make_pair(make_pair(1, i), j));
}
//cout << cnt << " " << cal << endl;
//cout << "end" << endl;
res += cnt;
}
}
}
cout << res;
}
/***
5 5
RGWRR
GRRGW
WRGWR
RGWRG
XWRGW
***/
