#include<bits/stdc++.h>
using namespace std;
ostream& operator<<(ostream &out, string str) {
for(char c : str) out << c;
return out;
}
template<class L, class R> ostream& operator<<(ostream &out, pair<L, R> p) {
return out << "(" << p.first << ", " << p.second << ")";
}
template<class T> auto operator<<(ostream &out, T a) -> decltype(a.begin(), out) {
out << "{";
for(auto it = a.begin(); it != a.end(); it = next(it))
out << (it != a.begin() ? ", " : "") << *it;
return out << "}";
}
void dump() { cerr << "\n"; }
template<class T, class... Ts> void dump(T a, Ts... x) {
cerr << a << ", ";
dump(x...);
}
#ifdef DEBUG
# define debug(...) cerr << "[" #__VA_ARGS__ "]: ", dump(__VA_ARGS__)
#else
# define debug(...) false
#endif
#define REP(i, n) for(int i = 0; i < n; i++)
#define FOR(i, a, b) for(int i = a; i <= b; i++)
#define ST first
#define ND second
template<class T> int size(T && a) { return a.size(); }
using LL = long long;
using PII = pair<int, int>;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
int n, m;
cin >> n >> m;
map<char, int> id = {{'R', 1}, {'G', 2}, {'W', 3}};
vector<vector<int>> a(n, vector<int>(m));
REP(i, n) REP(j, m) {
char c;
cin >> c;
a[i][j] = id[c];
}
vector<vector<bool>> v(n, vector<bool>(m));
vector<vector<bool>> h(n, vector<bool>(m));
FOR(i, 1, n - 2) REP(j, m) {
if(a[i][j] != 2) continue;
if(a[i - 1][j] == 1 && a[i + 1][j] == 3)
v[i][j] = true;
}
REP(i, n) FOR(j, 1, m - 2) {
if(a[i][j] != 2) continue;
if(a[i][j - 1] == 1 && a[i][j + 1] == 3)
h[i][j] = true;
}
int ans = 0;
FOR(s, 0, n + m - 2) {
int j = min(m - 1, s);
int i = s - j;
array<int, 2> dp = {0, 0};
while(0 <= j && i < n) {
auto nxt = dp;
for(int &q : nxt) q = max(nxt[0], nxt[1]);
debug(i, j);
if(v[i][j]) nxt[1] = max(nxt[1], dp[1] + 1);
if(h[i][j]) nxt[0] = max(nxt[0], dp[0] + 1);
j--, i++;
dp = nxt;
}
debug(s, dp);
ans += max(dp[0], dp[1]);
}
cout << ans << "\n";
}
