#include <bits/stdc++.h>
#define int long long
using namespace std;
#pragma GCC optimize("Ofast")
int r;
int c;
void once(vector<string>& input, vector<vector<vector<int>>>& dp, int rr, int cc) {
int umd = 0;
if (rr-1 >= 0 && rr+1 < r) {
if (input[rr-1][cc] == 'W' && input[rr][cc] == 'G' && input[rr+1][cc] == 'R') {
umd++;
}
}
int lmr = 0;
if (cc-1 >= 0 && cc+1 < c) {
if (input[rr][cc-1] == 'R' && input[rr][cc] == 'G' && input[rr][cc+1] == 'W') {
lmr++;
}
}
if (rr > 0 && cc > 0) {
dp[rr][cc][0] = max(dp[rr-1][cc-1][0], max(dp[rr-1][cc-1][1], dp[rr-1][cc-1][2]));
dp[rr][cc][1] = max(dp[rr-1][cc-1][0], dp[rr-1][cc-1][1]) + umd;
dp[rr][cc][2] = max(dp[rr-1][cc-1][0], dp[rr-1][cc-1][2]) + lmr;
} else {
dp[rr][cc][0] = 0;
dp[rr][cc][1] = umd;
dp[rr][cc][2] = lmr;
}
}
int solve(vector<string>& grid, int rr) {
return 1;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
cin >> r >> c;
vector<string> input(r);
vector<vector<vector<int>>> dp(r, vector<vector<int>>(c, vector<int>(3, 0)));
for (auto& i : input) cin >> i;
for (int i = 0;i < c;i++) {
for (int rr = 0;rr < r/2;rr++) {
swap(input[rr][i], input[r-rr-1][i]);
}
}
for (int rr = 0;rr < r;rr++) {
for (int cc = 0;cc < c;cc++) {
once(input, dp, rr, cc);
}
}
int sum = 0;
for (int cc = 0;cc < c;cc++) {
sum += max(dp[r-1][cc][0], max(dp[r-1][cc][1], dp[r-1][cc][2]));
}
for (int rr = 0;rr < r-1;rr++) {
sum += max(dp[rr][c-1][0], max(dp[rr][c-1][1], dp[rr][c-1][2]));
}
cout << sum << "\n";
}
