#include <bits/stdc++.h>
using namespace std;
#define sp " "
#define endl "\n";
#define fastio() cin.tie(0), ios_base::sync_with_stdio(0)
#define pb push_back
#define pii pair<int, int>
#define st first
#define nd second
#define N 3005
const int modulo = 1e9 + 7;
int arr[N][N], root[N * N], done[N][N];
pii sz[N];
set<int> roots;
int find(int node)
{
if (root[node] == node) return node;
return root[node] = find(root[node]);
}
void uni(int a, int b)
{
a = find(a), b = find(b);
if (sz[a].st + sz[a].nd < sz[b].st + sz[b].nd) swap(a, b);
if (a == b) return;
root[b] = a;
roots.erase(b);
sz[a].st += sz[b].st, sz[a].nd += sz[b].nd;
}
int32_t main()
{
fastio();
map<char, int> val;
val['R'] = 1, val['G'] = 2, val['W'] = 3;
int n, m;
cin>>n>>m;
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= m; j++)
{
char tmp;
cin>>tmp;
arr[i][j] = val[tmp];
}
}
for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) done[i][j] = (i - 1) * m + j;
for (int i = 1; i <= n * m; i++) root[i] = i, roots.insert(i);
int ans = 0;
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= m; j++)
{
int val = 0, f = 1;
for (int k = i; k <= i + 2; k++)
{
val += arr[k][j] * f;
f *= 10;
}
if (val == 321)
{
//cout<<"v "<<i<<sp<<j<<endl;
sz[find(done[i][j])].st++;
for (int k = i + 1; k <= i + 2; k++)
uni(done[i][j], done[k][j]);
}
val = 0, f = 1;
for (int k = j; k <= j + 2; k++)
{
val += arr[i][k] * f;
f *= 10;
}
if (val == 321)
{
//cout<<"> "<<i<<sp<<j<<endl;
sz[find(done[i][j])].nd++;
for (int k = j + 1; k <= j + 2; k++)
uni(done[i][j], done[i][k]);
}
}
}
for (auto i : roots)
{
ans += max(sz[i].st, sz[i].nd);
}
cout<<ans<<endl;
cerr << "time taken : " << (float)clock() / CLOCKS_PER_SEC << " seconds\n";
}
