#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
const bool typetest = 0;
const int N = 3e3 + 5;
const ll Inf = 1e17;
int n, m;
string s[N];
int dp[N][2];
void Read()
{
cin >> m >> n;
for (int i = 1; i <= m; ++i)
{
cin >> s[i];
s[i] = " " + s[i];
}
}
inline void Max(int &x, int y)
{
if (x < y)
x = y;
}
void Solve()
{
int ans(0);
for (int t = 4; t <= m + n; ++t)
{
for (int i = 1; i <= n; ++i)
dp[i][0] = dp[i][1] = 0;
for (int i = t <= m ? 1 : t - m; i < t && i <= n; ++i)
{
if (i > 2 && s[t - i][i - 2] == 'R' && s[t - i][i - 1] == 'G' && s[t - i][i] == 'W')
++dp[i][0];
if (t - i > 2 && s[t - i - 2][i] == 'R' && s[t - i - 1][i] == 'G' && s[t - i][i] == 'W')
++dp[i][1];
Max(dp[i + 1][0], dp[i][0]);
Max(dp[i + 1][1], dp[i][0]);
Max(dp[i + 3][0], dp[i][1]);
Max(dp[i + 1][1], dp[i][1]);
}
ans += max(dp[min(t - 1, n)][0], dp[min(t - 1, n)][1]);
}
cout << ans;
}
int32_t main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t(1);
if (typetest)
cin >> t;
for (int _ = 1; _ <= t; ++_)
{
Read();
Solve();
}
}
