#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
//using namespace __gnu_pbds;
#define speed ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define russian setlocale(LC_ALL,"Russian_Russia.20866");
#define file freopen("onlyone.in", "r", stdin), freopen("onlyone.out", "w", stdout);
#define ll long long
//#define int long long
#define ull unsigned long long
#define ld long double
#define pll pair<ll, ll>
#define pii pair<int, int>
#define all(s) s.begin(), s.end()
#define pb push_back
#define ins insert
#define mp make_pair
#define sz(x) x.size()
#define F first
#define S second
#define lb lower_bound
#define ub upper_bound
#define mem(x) memset(x, 0, sizeof(x))
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const ll N = 3010;
const ll M = 600000;
const ll block = 316;
const ll mod = 1e9 + 7;
const ll P = 263;
const ld pi = acos(-1);
const ll inf = 1e9;
ll add(ll a, ll b) {
if(a + b < 0) return a + b + mod;
if(a + b >= mod) return a + b - mod;
return a + b;
}
ll sub(ll a, ll b) {
return (a - b + mod) % mod;
}
ll mul(ll a, ll b) {
return a * 1LL * b % mod;
}
ll binpow(ll a, ll n) {
ll res = 1;
while(n) {
if (n & 1) res = mul(res, a);
a = mul(a, a);
n >>= 1;
}
return res;
}
ll inv(ll x) {
return binpow(x, mod - 2);
}
int n, m;
char a[N][N];
string order = "RGW";
int dp[3][N][N];//0 - max both, 1 - horizontal, 2 - vetical
bool check(int x, int y) {
return (1 <= x && x <= n && 1 <= y && y <= m);
}
int horizontal(int i, int j) {
int ok = 1;
for(int k = 0; k < 3; k++) {
ok &= (check(i, j + k - 1) && a[i][j + k - 1] == order[k]);
}
return ok;
}
int vertical(int i, int j) {
int ok = 1;
for(int k = 0; k < 3; k++) {
ok &= (check(i + k - 1, j) && a[i + k - 1][j] == order[k]);
}
return ok;
}
void solve() {
cin >> n >> m;
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= m; j++) {
cin >> a[i][j];
}
}
dp[0][0][0] = dp[1][0][0] = dp[2][0][0] = 0;
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= m; j++) {
dp[0][i][j] = max({dp[0][i][j], dp[1][i - 1][j + 1], dp[2][i - 1][j + 1]});
dp[1][i][j] = max(dp[0][i][j], dp[1][i - 1][j + 1] + horizontal(i, j));
dp[2][i][j] = max(dp[0][i][j], dp[2][i - 1][j + 1] + vertical(i, j));
}
}
int ans = 0;
for(int i = 1; i <= n; i++) ans += max(dp[1][i][1], dp[2][i][1]);
for(int j = 2; j <= m; j++) ans += max(dp[1][n][j], dp[2][n][j]);
cout << ans << '\n';
}
signed main() {
speed;
//file
int test = 1;
//cin >> test;
while(test--) {
solve();
}
}
