#include<bits/stdc++.h>
using namespace std;
int n, m;
char a[3005][3005];
bool okh[3005][3005], okv[3005][3005];
int dp[3002][3002][3];
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> m;
for(int i = 1; i <= n; ++i)
cin >> (a[i] + 1);
for(int i = 1; i <= n; ++i)
for(int j = 1; j <= m; ++j)
{
if(a[i][j-1] == 'R' && a[i][j] == 'G' && a[i][j+1] == 'W')
okh[i][j] = 1;
if(a[i-1][j] == 'R' && a[i][j] == 'G' && a[i+1][j] == 'W')
okv[i][j] = 1;
}
int L = 1, C = 1;
int ans = 0;
for(int i = 2; i <= n+m; ++i)
{
int sL = L, sC = C;
dp[sL][sC][0] = 0;
dp[sL][sC][1] = okv[sL][sC];
dp[sL][sC][2] = okh[sL][sC];
--sL, ++sC;
while(sL && sC <= m)
{
for(int j = 0; j <= 2; ++j)
dp[sL][sC][0] = max(dp[sL][sC][0], dp[sL + 1][sC - 1][j]);
dp[sL][sC][1] = max(dp[sL + 1][sC - 1][1], dp[sL + 1][sC - 1][0]) + okv[sL][sC];
dp[sL][sC][2] = max(dp[sL + 1][sC - 1][2], dp[sL + 1][sC - 1][0]) + okh[sL][sC];
--sL, ++sC;
}
++L;
if(L > n)
{
L = n;
++C;
}
++sL, --sC;
ans = ans + max(dp[sL][sC][0], max(dp[sL][sC][1], dp[sL][sC][2]));
}
cout << ans;
return 0;
}
