#include <bits/stdc++.h>
#define ll long long
using namespace std;
ll dp[3007][3];
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
ll n,m;
cin >> n >> m;
vector<vector<char>> a(n+1, vector<char>(m+1));
for (int i=1; i<=n; i++) {
for (int j=1; j<=m; j++) {
cin >> a[i][j];
}
}
ll res = 0;
for (int d=2; d<=n+m; d++) {
ll is = max(d-m, 1LL);
ll ie = min(n, d-1LL);
vector<ll> v;
for (int i=is; i<=ie; i++) {
ll j = d-i;
if (a[i][j]=='G') v.push_back(i);
}
if (v.empty()) continue;
ll k = v.size();
for (int i=0; i<=k; i++) dp[i][0] = dp[i][1] = dp[i][2] = -1e18;
dp[0][0] = 0;
for (int k1=1; k1<=k; k1++) {
ll i = v[k1-1];
ll j = d-i;
dp[k1][0] = max({dp[k1-1][0], dp[k1-1][1], dp[k1-1][2]});
bool c1 = (i>1 && i<n && a[i-1][j]=='R' && a[i+1][j]=='W');
bool c2 = (j>1 && j<m && a[i][j-1]=='R' && a[i][j+1]=='W');
bool c3 = (k1>1 && v[k1-2]==i-1);
if (c1) {
if (c3) dp[k1][1] = max(dp[k1-1][0], dp[k1-1][1])+1;
else dp[k1][1] = max({dp[k1-1][0], dp[k1-1][1], dp[k1-1][2]})+1;
}
if (c2) {
if (c3) dp[k1][2] = max(dp[k1-1][0], dp[k1-1][2])+1;
else dp[k1][2] = max({dp[k1-1][0], dp[k1-1][1], dp[k1-1][2]})+1;
}
}
res+=max({dp[k][0], dp[k][1], dp[k][2]});
}
cout << res;
}
