/*
Zadanie: Dango Maker
Autor: Tomasz Kwiatkowski
*/
#include <bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
using namespace std;
typedef long long ll;
const int MAXN = 3e3 + 7;
const int INF = 1e9 + 7;
char color[MAXN][MAXN];
pair<int, int> dp[MAXN][MAXN];
pair<int, int> RGW(int i, int j)
{
pair<int, int> res = {false, false};
if (color[i][j] == 'R' && color[i][j+1] == 'G' && color[i][j+2] == 'W')
res.fi = true;
if (color[i][j] == 'R' && color[i+1][j] == 'G' && color[i+2][j] == 'W')
res.se = true;
return res;
}
int main()
{
ios_base::sync_with_stdio(0), cin.tie(0);
int n, m;
cin >> n >> m;
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= m; ++j)
cin >> color[i][j];
}
int ans = 0;
for (int j = 1; j <= m; ++j) {
pair<int, int> prv = {0, 0};
for (int i = 1; i <= min(n, j); ++i) {
auto [h, v] = RGW(i, j - i + 1);
// printf("[%d, %d]\t", h, v);
dp[i][j - i + 1].fi = dp[i - 1][j - i + 1 + 1].fi + h;
dp[i][j - i + 1].se = max(dp[i - 1][j - i + 1 + 1].fi, dp[i - 1][j - i + 1 + 1].se) + v;
if (i >= 3) {
dp[i][j - i + 1].fi = max(dp[i][j - i + 1].fi, dp[i - 3][j - i + 1 + 3].se + h);
}
// printf("dp[%d][%d] = (%d, %d)\n", i, j - i + 1, dp[i][j - i + 1].fi, dp[i][j - i + 1].se);
prv = dp[i][j - i + 1];
}
ans += max(prv.fi, prv.se);
}
for (int i = 2; i <= n; ++i) {
pair<int, int> prv = {0, 0};
for (int j = m; j >= max(m - n + i, 1); --j) {
auto [h, v] = RGW(i + m - j, j);
// printf("[%d, %d]\t", h, v);
dp[i + m - j][j].fi = dp[i + m - j - 1][j + 1].fi + h;
dp[i + m - j][j].se = max(dp[i + m - j - 1][j + 1].fi, dp[i + m - j - 1][j + 1].se) + v;
if (i + m - j >= 3) {
dp[i + m - j][j].fi = max(dp[i + m - j][j].fi, dp[i + m - j - 3][j + 3].se + h);
}
// printf("dp[%d][%d] = (%d, %d)\n", i + m - j, j, dp[i + m - j][j].fi, dp[i + m - j][j].se);
prv = dp[i + m - j][j];
}
ans += max(prv.fi, prv.se);
}
cout << ans << '\n';
return 0;
}
