//#include"holiday.h"
#include <bits/stdc++.h>
#define ll long long
#define rep(i,m,n) for(int i=(m); i<=(n); i++)
#define reb(i,m,n) for(int i=(m); i>=(n); i--)
#define pii pair<int,int>
#define pll pair<ll,ll>
#define MP make_pair
#define fs first
#define se second
#define bit(msk, i) ((msk >> i) & 1)
#define iter(id, v) for(auto id : v)
#define pb push_back
#define SZ(v) (ll)v.size()
#define ALL(v) v.begin(),v.end()
using namespace std;
mt19937_64 rd(chrono :: steady_clock :: now ().time_since_epoch().count());
ll Rand (ll l, ll r) { return uniform_int_distribution<ll> (l, r) (rd); }
const int N = 3e3 + 7;
int Mod = 2e9 + 7;///lon
const ll INF = 2e9;
const ll BASE = 137;
const int szBL = 450;
int n, m;
char a[N][N];
int dp[N][N];
void solution () {
cin >> n >> m;
rep (i, 1, n) {
string s;
cin >> s;
rep (j, 1, m) a[i][j] = s[j - 1];
}
auto dangoN = [&] (int i, int j) {
return a[i][j - 1] == 'R' && a[i][j] == 'G' && a[i][j + 1] == 'W';
};
auto dangoD = [&] (int i, int j) {
return a[i - 1][j] == 'R' && a[i][j] == 'G' && a[i + 1][j] == 'W';
};
int res = 0;
rep (T, 1, n + m) {
rep (i, 1, n) {
int j = T - i;
if (j > m || j <= 0) {
rep (k, 0, 2) dp[i][k] = dp[i - 1][k];
continue;
}
dp[i][0] = max({dp[i - 1][1], dp[i - 1][0], dp[i - 1][2]});
dp[i][1] = max(dp[i - 1][0], dp[i - 1][1]) + dangoN(i, j);
dp[i][2] = max(dp[i - 1][0], dp[i - 1][2]) + dangoD(i, j);
}
res += max({dp[n][0], dp[n][1], dp[n][2]});
}
cout << res <<"\n";
}
#define file(name) freopen(name".inp","r",stdin); \
freopen(name".out","w",stdout);
int main () {
// file("c");
ios_base :: sync_with_stdio(false); cin.tie(0); cout.tie(0);
int num_Test = 1;
// cin >> num_Test;
while (num_Test--)
solution();
}
/*
no bug challenge +10
5 5
01101
10001
00110
10101
00100
*/
