#define here cerr<<"===========================================\n"
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#define ld double
#define ll int
#define llinf 100000000000000000LL // 10^17
#define pb push_back
#define popb pop_back
#define fi first
#define sc second
#define endl '\n'
#define pll pair<ll,ll>
#define pld pair<ld,ld>
#define sz(a) (ll)(a.size())
#define all(a) a.begin(),a.end()
#define ceri(a,l,r) {for(ll i_ = l;i_<=r;i_++) cerr<<a[i_]<< " ";cerr<<endl;}
#define daj_mi_malo_vremena ios_base::sync_with_stdio(false);cerr.tie(0);cout.tie(0);cin.tie(0);
using namespace std;
using namespace __gnu_pbds;
/*
ll add(ll x,ll y){
x+=y;
if(x<0){
x%=mod;
x+=mod;
}else{
if(x>=mod) x%=mod;
}
return x;
}
ll mul(ll a,ll b){
ll ans = (a*b)%mod;
if(ans<0) ans+=mod;
return ans;
}
*/
typedef tree<int,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
typedef tree<int,null_type,less_equal<ll>,rb_tree_tag,tree_order_statistics_node_update> ordered_multiset;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll rnd(ll l,ll r){
return uniform_int_distribution<ll>(l,r)(rng);
}
#define maxn 6005
ll n,m;
ll a[maxn][maxn];
ll dp[maxn][2][2];
bool moe[maxn][maxn][2];
bool okright(ll i,ll j){
if(j+2>m) return 0;
return (a[i][j]==1)&&(a[i][j+1]==2)&&(a[i][j+2]==3);
}
bool okdown(ll i,ll j){
if(i+2>n) return 0;
return (a[i][j]==1)&&(a[i+1][j]==2)&&(a[i+2][j]==3);
}
ll ans = 0;
int main(){
daj_mi_malo_vremena
cin >> n >> m;
for(ll i = 1;i<=n;i++){
string s; cin >> s;
for(ll j = 1;j<=m;j++){
if(s[j-1]=='R') a[i][j] = 1;
if(s[j-1]=='G') a[i][j] = 2;
if(s[j-1]=='W') a[i][j] = 3;
}
}
for(ll i = 1;i<=n;i++){
for(ll j = 1;j<=m;j++){
moe[i+j][i][0] = okright(i,j);
moe[i+j][i][1] = okdown(i,j);
}
}
for(ll z = 2;z<=n+m;z++){
for(ll i = 0;i<=n;i++) for(ll x = 0;x<=1;x++) for(ll y = 0;y<=1;y++) dp[i][x][y] = -llinf;
dp[0][0][0] = 0;
for(ll i = 1;i<=n;i++){
for(ll x = 0;x<=1;x++){
for(ll y = 0;y<=1;y++){
dp[i][0][x] = max(dp[i][0][x],dp[i-1][x][y]);
if(moe[z][i][0]&&x==0&&y==0) dp[i][0][x] = max(dp[i][0][x],dp[i-1][x][y]+1);
if(moe[z][i][1]) dp[i][1][x] = max(dp[i][1][x],dp[i-1][x][y]+1);
}
}
}
ll cur = 0;
for(ll x = 0;x<=1;x++) for(ll y = 0;y<=1;y++) cur = max(cur,dp[n][x][y]);
ans+=cur;
}
cout<<ans<<endl;
return 0;
}
/*
5 5
RGRGW
GRRGW
WGGWR
RWRGW
RGWGW
4 4
RGWR
GRRG
WGGW
WWWR
3 4
RGWR
GRGG
RGWW
*/
