#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
#if 0
const int MOD = ;
inline int lgput(int a, int b) {
int ans = 1;
while(b > 0) {
if(b & 1) ans = (1LL * ans * a) % MOD;
b >>= 1;
a = (1LL * a * a) % MOD;
}
return ans;
}
inline void mod(int &x) {
if(x >= MOD)
x -= MOD;
}
inline void add(int &x, int y) {
x += y;
mod(x);
}
inline void sub(int &x, int y) {
x += MOD - y;
mod(x);
}
inline void mul(int &x, int y) {
x = (1LL * x * y) % MOD;
}
inline int inv(int x) {
return lgput(x, MOD - 2);
}
#endif
#if 0
int fact[], invfact[];
inline void prec(int n) {
fact[0] = 1;
for(int i = 1; i <= n; i++) {
fact[i] = (1LL * fact[i - 1] * i) % MOD;
}
invfact[n] = lgput(fact[n], MOD - 2);
for(int i = n - 1; i >= 0; i--) {
invfact[i] = (1LL * invfact[i + 1] * (i + 1)) % MOD;
}
}
inline int comb(int n, int k) {
if(n < k) return 0;
return (1LL * fact[n] * (1LL * invfact[k] * invfact[n - k] % MOD)) % MOD;
}
#endif
using namespace std;
const int MAXN = 3005;
char mat[MAXN + 1][MAXN + 1];
bool u[MAXN + 1][MAXN + 1], r[MAXN + 1][MAXN + 1];
short dp[MAXN + 1][MAXN + 1][3];
int main() {
#if 0
ifstream cin("A.in");
ofstream cout("A.out");
#endif
int i, j, n, m;
ios::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
cin >> n >> m;
for(i = 1; i <= n; i++) {
cin >> mat[i] + 1;
}
for(i = 1; i <= n; i++) {
for(j = 1; j <= m; j++) {
if(mat[i][j] == 'G') {
if(mat[i - 1][j] == 'R' && mat[i + 1][j] == 'W') {
u[i][j] = 1;
}
if(mat[i][j - 1] == 'R' && mat[i][j + 1] == 'W') {
r[i][j] = 1;
}
}
}
}
int ls = 1, cs = 1, ans = 0;
for(i = 2; i <= n + m; i++) {
int l = ls, c = cs;
dp[l][c][0] = 0;
dp[l][c][1] = u[l][c];
dp[l][c][2] = r[l][c];
l--, c++;
while(l > 0 && c <= m) {
for(j = 0; j < 3; j++) {
dp[l][c][0] = max(dp[l][c][0], dp[l + 1][c - 1][j]);
}
if(u[l][c]) {
dp[l][c][1] = max(dp[l + 1][c - 1][1], dp[l + 1][c - 1][0]) + 1;
}
if(r[l][c]) {
dp[l][c][2] = max(dp[l + 1][c - 1][2], dp[l + 1][c - 1][0]) + 1;
}
l--, c++;
}
ls++;
if(ls == n + 1) {
ls = n, cs++;
}
l++, c--;
ans += max(max(dp[l][c][0], dp[l][c][1]), dp[l][c][2]);
}
cout << ans;
return 0;
}
