#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define maxn 1000010
#define N 5010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define int long long
#define inf (int)1e18
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1LL << j))
#define onbit(i, j) (i | (1LL << j))
#define vi vector<int>
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
if (a > b)
{
a = b;
return true;
}
return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
if (a < b)
{
a = b;
return true;
}
return false;
}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
int f[2 * N][3],a[N][N],good[N][N];
int n,m;
bool down(int i,int j)
{
return a[i][j] == 0 and a[i + 1][j] == 1 and a[i + 2][j] == 2;
}
bool right(int i,int j)
{
return a[i][j] == 0 and a[i][j + 1] == 1 and a[i][j + 2] == 2;
}
main()
{
#define name "TASK"
if (fopen(name ".inp", "r"))
{
freopen(name ".inp", "r", stdin);
freopen(name ".out", "w", stdout);
}
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> m;
fo(i,1,n) fo(j,1,m)
{
char t;
cin >> t;
if(t == 'R') a[i][j] = 0;
if(t == 'G') a[i][j] = 1;
if(t == 'W') a[i][j] = 2;
}
fo(i,1,n) fo(j,1,m)
{
if(down(i,j)) good[i + 1][j] = onbit(good[i + 1][j],1);
if(right(i,j)) good[i][j + 1] = onbit(good[i][j + 1],2);
}
int ans = 0;
fo(sum,2,n + m)
{
int res = 0;
fo(i,1,n)
{
int j = sum - i;
f[i][0] = max({f[i - 1][0],f[i - 1][1],f[i - 1][2]});
f[i][1] = f[i][2] = 0;
if(bit(good[i][j],1)) maximize(f[i][1],max(f[i - 1][1],f[i - 1][0]) + 1);
if(bit(good[i][j],2)) maximize(f[i][2],max(f[i - 1][0],f[i - 1][2]) + 1);
maximize(res,max({f[i][0],f[i][1],f[i][2]}));
}
ans += res;
}
cout << ans;en;
}
