//by szh
#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pii pair<int,int>
#define pll pair<long long,long long>
#define pb push_back
#define debug(x) cerr<<#x<<"="<<x<<endl
#define pq priority_queue
#define inf 0x3f
#define rep(i,a,b) for (int i=a;i<(b);i++)
#define MP make_pair
#define SZ(x) (int(x.size()))
#define ll long long
#define mod 1000000007
#define ALL(x) x.begin(),x.end()
void inc(int &a,int b) {a=(a+b)%mod;}
void dec(int &a,int b) {a=(a-b+mod)%mod;}
int lowbit(int x) {return x&(-x);}
ll p0w(ll base,ll p) {ll ret=1;while(p>0){if (p%2ll==1ll) ret=ret*base%mod;base=base*base%mod;p/=2ll;}return ret;}
const int maxn = 3010;
int n,m;
int grid[maxn][maxn];
int dp[maxn][maxn][2];
int main() {
// freopen("input.txt","r",stdin);
std::ios::sync_with_stdio(false);cin.tie(0);
cin>>n>>m;
memset(grid,-1,sizeof(grid));
rep(i,1,n+1) {
string s;cin>>s;
rep(j,1,m+1) {
if (s[j-1]=='R') grid[i][j]=0;
else if (s[j-1]=='G') grid[i][j]=1;
else grid[i][j]=2;
}
}
int ans = 0;
rep(i,1,n+1)
rep(j,1,m+1) {
if (grid[i][j]==1) {
dp[i][j][0] = dp[i][j][1] = max(dp[i-1][j+1][1],dp[i-1][j+1][0]);
if (grid[i-1][j]==0 and grid[i+1][j]==2) dp[i][j][1] = max(dp[i][j][1],dp[i-1][j+1][1] + 1);
if (grid[i][j-1]==0 and grid[i][j+1]==2) dp[i][j][0] = max(dp[i][j][0],dp[i-1][j+1][0] + 1);
if (grid[i+1][j-1]!=1) ans += max(dp[i][j][0],dp[i][j][1]);
}
}
cout<<ans;
return 0;
}
