#include<bits/stdc++.h>
using namespace std;
vector<vector<char>> a;
bool dangoD (int i, int j) { return a[i-1][j]=='R' && a[i][j]=='G' && a[i+1][j]=='W'; }
bool dangoR (int i, int j) { return a[i][j-1]=='R' && a[i][j]=='G' && a[i][j+1]=='W'; }
int main() {
cin.tie(0)->sync_with_stdio(false);
int n, m;
cin >> n >> m;
a.assign(n+2, vector<char>(m+2, '#'));
for (int i = 1; i <= n; ++i) {
string s;
cin >> s;
for (int j = 1; j <= m; ++j) {
a[i][j]=s[j-1];
}
}
int res=0;
vector<vector<int>> dp(m+n, vector<int>(3, 0));
for (int t = 1; t <= n+m; ++t) {
for (int i = 1; i <= n; ++i) {
int j=t-i;
if (j>m || j<=0) {
for (int k = 0; k < 3; ++k) dp[i][k]=dp[i-1][k];
continue;
}
dp[i][0]=max(dp[i-1][0], max(dp[i-1][1], dp[i-1][2]));
dp[i][1]=max(dp[i-1][0], dp[i-1][1])+dangoR(i, j);
dp[i][2]=max(dp[i-1][0], dp[i-1][2])+dangoD(i, j);
} res+=max(dp[n][0], max(dp[n][1], dp[n][2]));
} cout << res << '\n';
return 0;
}
