#include <bits/stdc++.h>
using namespace std;
const int DIM = 3109;
const int di[9] = {-2, -2, -2, -1, -1, -1, 0, 0, 0};
const int dj[9] = {0, 1, 2, 0, 1, 2, 0, 1, 2};
char str[DIM][DIM];
pair<short, short> lef[DIM][DIM], rig[DIM][DIM];
bitset<DIM> mrk[DIM], val1[DIM], val2[DIM];
bool match(int x, int y, int &ans) {
if (mrk[x][y]) {
return false; }
mrk[x][y] = true;
for (int d = 0; d < 9; ++d) {
int xx = x + di[d], yy = y + dj[d];
if (xx >= 1 and val2[xx][yy] and rig[xx][yy].first == 0) {
lef[x][y] = make_pair(xx, yy);
rig[xx][yy] = make_pair(x, y);
--ans; return true; } }
for (int d = 0; d < 9; ++d) {
int xx = x + di[d], yy = y + dj[d];
if (xx >= 1 and val2[xx][yy] and match(rig[xx][yy].first, rig[xx][yy].second, ans)) {
lef[x][y] = make_pair(xx, yy);
rig[xx][yy] = make_pair(x, y);
return true; } }
return false; }
int main(void) {
#ifdef HOME
freopen("dango.in", "r", stdin);
freopen("dango.out", "w", stdout);
#endif
int n, m; cin >> n >> m;
for (int i = 1; i <= n; ++i) {
cin >> (str[i] + 1); }
int ans = 0;
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= m; ++j) {
if (j + 2 <= m and str[i][j] == 'R' and str[i][j + 1] == 'G' and str[i][j + 2] == 'W') {
val1[i][j] = true; ++ans; }
if (i + 2 <= n and str[i][j] == 'R' and str[i + 1][j] == 'G' and str[i + 2][j] == 'W') {
val2[i][j] = true; ++ans; } } }
bool ok; do {
ok = false;
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= m; ++j) {
if (val1[i][j] and lef[i][j].first == 0 and match(i, j, ans)) {
ok = true; } } }
} while (ok);
cout << ans;
return 0; }
