#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
template <class T1, class T2>
bool maximize(T1 &a, T2 b){
if (a < b) {a = b; return true;}
return false;
}
template <class T1, class T2>
bool minimize(T1 &a, T2 b){
if (a > b) {a = b; return true;}
return false;
}
template <class T>
void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
for(auto item: container) out << item << separator;
out << finish;
}
template <class T>
void remove_dup(vector<T> &a){
sort(ALL(a));
a.resize(unique(ALL(a)) - a.begin());
}
struct DSU{
int n;
vector<int> parent, sz;
DSU(int _n){
n = _n;
parent.resize(n); sz.resize(n, 1);
for(int i = 0; i<n; ++i) parent[i] = i;
}
int find_set(int u){return (u == parent[u]) ? u : (parent[u] = find_set(parent[u]));}
bool same_set(int u, int v){return find_set(u) == find_set(v);}
bool join_set(int u, int v){
u = find_set(u), v = find_set(v);
if (u != v){
if (sz[u] < sz[v]) swap(u, v);
parent[v] = u;
sz[u] += sz[v];
return true;
}
return false;
}
int get_size(int u){return sz[find_set(u)];}
};
int main(void){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int n, m; cin >> n >> m;
vector<string> s(n);
for(int i = 0; i<n; ++i) cin >> s[i];
DSU mst(n * m);
for(int i = 0; i<n; ++i) for(int j = 0; j<m; ++j) if (s[i][j] == 'G'){
int cur = i * m + j;
if (i > 0 && i + 1 < n && s[i-1][j] == 'R' && s[i+1][j] == 'W'){
mst.join_set(cur - m, cur + m);
}
if (j > 0 && j + 1 < m && s[i][j-1] == 'R' && s[i][j+1] == 'W'){
mst.join_set(cur - 1, cur + 1);
}
}
int ans = 0;
for(int i = 0; i<n*m; ++i) if (i == mst.find_set(i)){
ans += mst.get_size(i) / 2;
}
cout << ans << "\n";
return 0;
}
