#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define pb push_back
#define pa pair<int, int>
#define pall pair<ll, int>
#define fi first
#define se second
#define TASK "test"
#define Size(x) (int) x.size()
#define all(x) x.begin(), x.end()
using namespace std;
template<typename T1, typename T2> bool mini (T1 &a, T2 b) {if(a > b) a = b; else return 0; return 1;}
template<typename T1, typename T2> bool maxi (T1 &a, T2 b) {if(a < b) a = b; else return 0; return 1;}
const int MOD = 1e9 + 7;
const int LOG = 20;
const int maxn = 3e3 + 7;
const ll oo = 1e18 + 69;
int n, m, dp[maxn][3];
char a[maxn][maxn];
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
//freopen(TASK".inp", "r", stdin);
//freopen(TASK".out", "w", stdout);
cin>>n>>m;
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= m; j++) cin>>a[i][j];
}
int ans = 0;
for(int d = 0; d <= n + m; d++) {
for(int i = 0; i <= n; i++) {
for(int t = 0; t < 3; t++) dp[i][t] = 0;
}
for(int i = 1; i <= n; i++) {
int j = d - i;
maxi(dp[i][1], dp[i - 1][1]);
maxi(dp[i][2], dp[i - 1][2]);
maxi(dp[i][1], dp[i - 1][2]);
if(j > m || j < 1) continue;
if(j - 2 >= 1 && a[i][j] == 'W' && a[i][j - 1] == 'G' && a[i][j - 2] == 'R') dp[i][1]++;
if(i - 3 >= 0 && a[i][j] == 'W' && a[i - 1][j] == 'G' && a[i - 2][j] == 'R') {
maxi(dp[i][2], max(dp[i - 3][1], dp[i - 3][2]) + 1);
maxi(dp[i][2], dp[i - 1][2] + 1);
maxi(dp[i][2], dp[i - 2][2] + 1);
}
}
ans += max(dp[n][1], dp[n][2]);
}
cout<<ans;
return 0;
}
