#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <string>
#include <cmath>
#include <cstdio>
#include <iomanip>
#include <fstream>
#include <cassert>
#include <cstring>
#include <unordered_set>
#include <unordered_map>
#include <numeric>
#include <ctime>
#include <bitset>
#include <complex>
#include <random>
using namespace std;
const int N = 3001;
int a[N][N];
int read() {
char c;
cin >> c;
if (c == 'R') return 0;
if (c == 'G') return 1;
if (c == 'W') return 2;
assert(false);
return -1;
}
int n, m;
int ok(int i, int j, int dir) {
if (dir == 0) {
if (i == 0 || i + 1 == n) return 0;
return a[i - 1][j] == 0 && a[i][j] == 1 && a[i + 1][j] == 2;
} else {
if (j == 0 || j + 1 == m) return 0;
return a[i][j - 1] == 0 && a[i][j] == 1 && a[i][j + 1] == 2;
}
}
int dp[3];
int ndp[3];
//0 - none
//1 - up
//2 - left
void rec(int cu, int cd) {
ndp[0] = max({dp[0], dp[1], dp[2]});
ndp[1] = max({dp[0], dp[1]}) + cu;
ndp[2] = max({dp[0], dp[2]}) + cd;
for (int i = 0; i < 3; i++) {
dp[i] = ndp[i];
ndp[i] = 0;
}
}
void init() {
fill(dp, dp + 3, 0);
fill(ndp, ndp + 3, 0);
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n >> m;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
a[i][j] = read();
}
}
int ans = 0;
for (int sm = 0; sm <= n + m; sm++) {
init();
for (int i = 0; i < n; i++) {
int j = sm - i;
if (j < 0 || j >= m) continue;
rec(ok(i, j, 0), ok(i, j, 1));
}
ans += max({dp[0], dp[1], dp[2]});
}
cout << ans << endl;
}
