#include<bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define X first
#define Y second
const int maxn = 3005;
int n,m;
char s[maxn][maxn];
int dp[maxn][3][3];
pii a[maxn*2][maxn];
int f(int cur, int x, int t0, int t1) {
if(x==n+1) return 0;
if(dp[x][t0][t1]==-1) {
dp[x][t0][t1] = f(cur,x+1,0,t0);
if(t0!=2 && t1!=2) {
dp[x][t0][t1] = max(dp[x][t0][t1], a[cur][x].X + f(cur,x+1,1,t0));
}
dp[x][t0][t1] = max(dp[x][t0][t1], a[cur][x].Y + f(cur,x+1,2,t0));
}
return dp[x][t0][t1];
}
int main() {
int i,j;
scanf("%d%d",&n,&m);
for(i=1;i<=n;i++) for(j=1;j<=m;j++) scanf(" %c",&s[i][j]);
for(i=1;i<=n;i++) {
for(j=1;j<=m;j++) {
int t0 = 0, t1 = 0;
if(s[i][j]=='R' && s[i][j+1]=='G' && s[i][j+2]=='W') {
t0 = 1;
}
if(s[i][j]=='R' && s[i+1][j]=='G' && s[i+2][j]=='W') {
t1 = 1;
}
a[i+j][i] = {t0,t1};
}
}
int ans = 0;
for(i=2;i<=n+m;i++) {
memset(dp,-1,sizeof(dp));
// printf("i = %d : %d\n",i,f(i,1,0,0));
ans += f(i,1,0,0);
}
printf("%d",ans);
}
