#include <bits/stdc++.h>
using namespace std;
int R, C, ans;
char G[3001][3001];
bool f[3001][3001][2]; // 0 is horizontal, 1 is vertical
int id[3001][3001][2];
int nn;
vector<int> adj[6001];
void dfs(int p, int x, int y, int z) {
if (id[x][y][z]) {
if (p) adj[p].push_back(id[x][y][z]);
return;
}
id[x][y][z] = ++nn;
adj[id[x][y][z]].clear();
if (p) adj[p].push_back(id[x][y][z]);
if (z) {
if (f[x][y][0]) dfs(id[x][y][z], x, y, 0);
if (y > 0 && f[x+1][y-1][0]) dfs(id[x][y][z], x+1, y-1, 0);
if (y > 1 && f[x+2][y-2][0]) dfs(id[x][y][z], x+2, y-2, 0);
} else {
if (f[x][y][1]) dfs(id[x][y][z], x, y, 1);
if (x > 0 && f[x-1][y+1][1]) dfs(id[x][y][z], x-1, y+1, 1);
if (x > 1 && f[x-2][y+2][1]) dfs(id[x][y][z], x-2, y+2, 1);
}
}
int dp[6001][4]; // left is first bit right is second bit
bool vis[6001];
vector<int> ladj, radj;
void comp(int d, int l, int r) {
vis[l] = vis[r] = 1;
ladj.clear(); radj.clear();
for (int i : adj[l]) if (!vis[i]) ladj.push_back(i);
for (int i : adj[r]) if (!vis[i]) radj.push_back(i);
if (!ladj.size() && !radj.size()) {
if (l) {
dp[d][0] = 0;
dp[d][1] = 1;
}
if (r) {
dp[d][2] = 1;
dp[d][3] = 2;
}
return;
}
if (l && r && ladj.size() == 1 && radj.size() == 1) {
comp(d+1, ladj[0], 0);
dp[d][0] = max(dp[d+1][0], dp[d+1][1]);
dp[d][1] = dp[d+1][0]+1;
dp[d][2] = dp[d+1][0]+1;
dp[d][3] = dp[d+1][0]+2;
} else if (l && r && ladj.size() == 2 && radj.size() == 1) {
if (ladj[0] == radj[0]) swap(ladj[0], ladj[1]);
comp(d+1, ladj[0], ladj[1]);
dp[d][0] = max(max(dp[d+1][0], dp[d+1][1]), max(dp[d+1][2], dp[d+1][3]));
dp[d][1] = dp[d+1][0]+1;
dp[d][2] = max(dp[d+1][0], dp[d+1][1])+1;
dp[d][3] = dp[d+1][0]+2;
} else if (l && r && radj.size() == 2 && ladj.size() == 1) {
if (radj[1] == ladj[0]) swap(radj[0], radj[1]);
comp(d+1, radj[0], radj[1]);
dp[d][0] = max(max(dp[d+1][0], dp[d+1][1]), max(dp[d+1][2], dp[d+1][3]));
dp[d][1] = max(dp[d+1][0], dp[d+1][2])+1;
dp[d][2] = dp[d+1][0]+1;
dp[d][3] = dp[d+1][0]+2;
} else if (l && r && ladj.size() == 0) {
comp(d+1, radj[0], 0);
dp[d][0] = max(dp[d+1][0], dp[d+1][1]);
dp[d][1] = dp[d][0]+1;
dp[d][2] = dp[d+1][0]+1;
dp[d][3] = dp[d+1][0]+2;
} else if (l && r && radj.size() == 0) {
comp(d+1, ladj[0], 0);
dp[d][0] = max(dp[d+1][0], dp[d+1][1]);
dp[d][1] = dp[d+1][0]+1;
dp[d][2] = dp[d][0]+1;
dp[d][3] = dp[d+1][0]+2;
} else if (l && !r && ladj.size() == 2) {
comp(d+1, ladj[0], ladj[1]);
dp[d][0] = max(max(dp[d+1][0], dp[d+1][1]), max(dp[d+1][2], dp[d+1][3]));
dp[d][1] = dp[d+1][0]+1;
} else if (l && !r && ladj.size() == 1) {
comp(d+1, ladj[0], 0);
dp[d][0] = max(dp[d+1][0], dp[d+1][1]);
dp[d][1] = dp[d+1][0]+1;
}
}
int main() {
scanf("%d%d", &R, &C);
for (int i = 0; i < R; i++) {
scanf("\n");
for (int j = 0; j < C; j++) {
scanf("%c", &G[i][j]);
}
}
for (int i = 0; i < R; i++) {
for (int j = 0; j < C; j++) {
if (i < R-2 && G[i][j] == 'R' && G[i+1][j] == 'G' && G[i+2][j] == 'W')
f[i][j][1] = 1;
if (j < C-2 && G[i][j] == 'R' && G[i][j+1] == 'G' && G[i][j+2] == 'W')
f[i][j][0] = 1;
}
}
for (int i = 0; i < R; i++) {
for (int j = 0; j < C; j++) {
for (int k = 0; k < 2; k++) {
if (!id[i][j][k] && f[i][j][k]) {
nn = 0;
dfs(0, i, j, k);
for (int z = 0; z <= nn; z++) vis[z] = 0;
comp(0, 1, 0);
ans += max(dp[0][0], dp[0][1]);
}
}
}
}
printf("%d\n", ans);
}
