#include <iostream>
#include <algorithm>
#include <vector>
#include <array>
using namespace std;
int solve(const vector<int>& a)
{
int n = a.size();
vector<array<int, 2>> f(n, {-1, -1});
if (a[0] & 1) f[0][0] = 1;
if (a[0] & 2) f[0][1] = 1;
for (int i = 0; i + 1 < n; ++i)
for (int j = 0; j < 2; ++j)
f[i + 1][j] = max(f[i][1 - j], f[i][j] + !!(a[i + 1] & (j + 1)));
return max(f.back()[0], f.back()[1]);
}
int main()
{
cin.tie(NULL); ios_base::sync_with_stdio(false);
int n, m; cin >> n >> m;
vector<string> tab(n);
for (int i = 0; i < n; ++i) cin >> tab[i];
int res = 0;
vector<vector<bool>> vst(n, vector<bool>(m));
for (int i = 0; i < n; ++i)
for (int j = 0; j < m; ++j)
if (tab[i][j] == 'G' && !vst[i][j]) {
vector<int> seq;
int u = i, v = j;
while (true) {
int x = 0;
x |= (u > 0 && u + 1 < n && tab[u - 1][v] == 'R' && tab[u + 1][v] == 'W');
x |= (v > 0 && v + 1 < m && tab[u][v - 1] == 'R' && tab[u][v + 1] == 'W') * 2;
if (!x) break;
vst[u][v] = true;
seq.push_back(x);
++u, --v;
if (u >= n || v < 0 || tab[u][v] != 'G') break;
}
if (!seq.empty()) res += solve(seq);
}
cout << res;
return 0;
}
