#include <bits/stdc++.h>
#define ll long long
#define pii pair<ll, ll>
#define st first
#define nd second
#define file "test"
#define rep(i, begin, end) for (ll i = (begin); i <= (end); i ++)
#define rrep(i, begin, end) for (ll i = (begin); i >= (end); i --)
using namespace std;
const long long INF = 1e18;
const long long N = 2e5 + 5;
ll dp[N][3], n, m, ans;
char a[3005][3005];
bool check(char a, char b, char c) {
return a == 'R' && b == 'G' && c == 'W';
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#ifndef ONLINE_JUDGE
//freopen(file".inp", "r", stdin); freopen(file".out", "w", stdout);
#endif
cin >> n >> m;
rep(i, 1, n) rep(j, 1, m) cin >> a[i][j];
rep(s, 2, n + m) {
ll res = 0;
rep(j, 1, m) dp[j][1] = dp[j][2] = 0;
rep(j, 1, m) {
int i = s - j;
if (i < 1 || i > n) continue;
// 1: vertical
// 2: horizontal
{ // no dango
dp[j][1] = max(dp[j - 1][1], dp[j - 1][2]);
if (j > 3)
dp[j][2] = max(dp[j - 1][2], dp[j - 3][1]);
}
{ // if can make dango
if (i > 2 && check(a[i - 2][j], a[i - 1][j], a[i][j]))
dp[j][1] ++;
if (j > 2 && check(a[i][j - 2], a[i][j - 1], a[i][j]))
dp[j][2] ++;
}
res = max(res, max(dp[j][1], dp[j][2]));
}
ans += res;
}
cout << ans << '\n';
return 0;
}
/** /\_/\
* (= ._.)
* / >🍵 \>🍮
dp on diagonal
**/
