#include<bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
using namespace std;
typedef long long ll;
#define ff first
#define ss second
#define pb push_back
#define all(x) (x).begin(),(x).end()
const int nax = 3005;
const int MOD = 1e9 + 7;
int n, m;
char grid[nax][nax];
int uses[nax][nax];
vector<int> p, setsz, seen;
vector<int> R, T;
int dp[2][2][2][2];
unordered_map<int,vector<int>> comp;
int findset(int x){return p[x] = p[x] == x? x: findset(p[x]);}
void unite(int i, int j)
{
int x = findset(i);
int y = findset(j);
if(x == y)
return ;
if(setsz[x] > setsz[y])
swap(x, y);
p[x] = y;
setsz[y] += setsz[x];
return ;
}
bool cmp(int i, int j)
{
if(R[i] == R[j])
return T[i] < T[j];
else
return R[i] < R[j];
}
bool collision(int i, int j)
{
if(T[i] == T[j])
return false;
if(R[i] > R[j])
swap(i, j);
if(R[i] == R[j])
return true;
if(R[j] <= R[i] + 2)
return (T[i] == 1);
return false;
}
void solve()
{
memset(uses, -1, sizeof(uses));
cin >> n >> m;
for(int i = 0; i < n; i++)
for(int j = 0; j < m; j++)
cin >> grid[i][j];
for(int i = 0; i< n - 2; i++)
{
for(int j = 0; j < m; j++)
{
if(grid[i][j] == 'R' && grid[i + 1][j] == 'G' && grid[i + 2][j] == 'W')
{
int idx = p.size();
T.pb(1);
R.pb(i);
uses[i][j] = uses[i + 1][j] = uses[i + 2][j] = idx;
p.pb(idx);
setsz.pb(1);
}
}
}
for(int i = 0; i < n; i++)
{
for(int j = 0; j < m - 2; j++)
{
if((grid[i][j] == 'R') && (grid[i][j + 1] == 'G') && (grid[i][j + 2] == 'W'))
{
int idx = p.size();
T.pb(0);
R.pb(i);
p.pb(idx);
setsz.pb(1);
if(uses[i][j] != -1)
unite(idx, uses[i][j]);
else
uses[i][j] = idx;
if(uses[i][j + 1] != -1)
unite(idx, uses[i][j + 1]);
else
uses[i][j + 1] = idx;
if(uses[i][j + 2] != -1)
unite(idx, uses[i][j + 2]);
else
uses[i][j + 2] = idx;
}
}
}
for(int i = 0; i < (int)(p.size()); i++)
comp[findset(i)].pb(i);
//cout << p.size() << endl;
seen.assign((int)(p.size()), 0);
int ans = 0;
for(int i =0; i < n; i++)
{
for(int j =0; j < m; j++)
{
if(uses[i][j] == -1)
continue;
int u = findset(uses[i][j]);
if(seen[u])
continue;
if(setsz[u] <= 2)
{
seen[u] = 1;
ans += 1;
continue;
}
sort(all(comp[u]), cmp);
int sz = setsz[u];
//cout << i << ' ' << j << ' ' << sz << endl;
for(int x = sz - 1; x >= 0; x--)
{
for(int b = 0; b <= 1; b++)
{
for(int bp = 0; bp <= min(x, 1); bp++)
{
for(int bpp = 0; bpp <= min(max(0,x - 1), 1); bpp++)
{
int avt = x > 1? comp[u][x - 2]: -1;
int prev = x > 0? comp[u][x - 1]: -1;
int cur = comp[u][x];
int nxt = x< sz - 1? comp[u][x + 1]: -1;
int me = (x & 1);
int ot = 1 - me;
if((b == 1 && bp == 1 && collision(cur, prev)) || (b == 1 && bpp == 1 && collision(cur, avt)))
{
dp[b][bp][bpp][me] = -MOD;
continue;
}
if(bp == 1 && bpp == 1 && collision(prev, avt))
{
dp[b][bp][bpp][me] = -MOD;
continue;
}
if(x == sz - 1)
{
dp[b][bp][bpp][me] = b;
continue;
}
int rep = 0;
if(bpp)
{
if(collision(nxt, avt))
rep = dp[0][b][bp][ot];
else
rep = max(dp[0][b][bp][ot], dp[1][b][bp][ot]);
}
else
rep = max(dp[0][b][bp][ot], dp[1][b][bp][ot]);
dp[b][bp][bpp][me] = b + rep;
}
}
}
}
ans += max(dp[0][0][0][0], dp[1][0][0][0]);
seen[u] = 1;
}
}
cout << ans ;
}
int32_t main()
{
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int tt = 1;
while(tt--)
solve();
}
