#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=2e9+1;
const ll INF=4e18;
const ll dy[8]={-1,0,1,0,1,1,-1,-1};
const ll dx[8]={0,-1,0,1,1,-1,1,-1};
template <typename T> inline bool chmax(T &a, T b) {
  return ((a < b) ? (a = b, true) : (false));
}
template <typename T> inline bool chmin(T &a, T b) {
  return ((a > b) ? (a = b, true) : (false));
}
struct UnionFind {
    vector<int> par;
    vector<int> edge;
    
    UnionFind(int n) : par(n, -1),edge(n, 0) {}

    int root(int x) {
        if (par[x] < 0) return x;
        else return par[x] = root(par[x]);
    }
    
    bool same(int x, int y) {
        return root(x) == root(y);
    }
    
    bool merge(int x, int y) {
        x = root(x); y = root(y);
        if (x == y) {
            edge[x]++;
            return false;
        }
        if (par[x] > par[y]) swap(x, y);
        par[x] += par[y];
        par[y] = x;
        edge[x] += edge[y]+1;
        return true;
    }
    
    int size(int x) {
        return -par[root(x)];
    }
};
ll maxN=1005000;
vvl tr(maxN);
vl val(maxN);
vvl dp(maxN,vl(2));//0なら自分を使わない、1なら自分を使う
void dfs(ll v){
  for(auto p:tr[v]){
    dfs(p);
    dp[v][0]+=max(dp[p][0],dp[p][1]);
    dp[v][1]+=dp[p][0];
  }
  dp[v][1]+=val[v];
}
int main(){
  ll n,m;cin >> n >>m;
  vector<string> g(n+2);
  rep(i,n){
    g[i+1]+='.';
    string s;cin >> s;
    g[i+1]+=s;
    g[i+1]+='.';
  }
  rep(i,m+2)g[0]+='.';
  rep(i,m+2)g[n+1]+='.';
  //rep(i,n+2)cout << g[i] << endl;
  n+=2;m+=2;
  UnionFind uf(n*m);
  rep(i,n){
    rep(j,m){
      rep(k,8){
        ll nx=i+dx[k],ny=j+dy[k];
        if(nx<0||ny<0||nx>=n||ny>=m)continue;
        if(g[i][j]=='x'&&g[nx][ny]=='x'){
          uf.merge(i*m+j,nx*m+ny);
        }
      }
    }
  }
  rep(i,n)rep(j,m){
    if(g[i][j]=='.')continue;
    val[uf.root(i*m+j)]=uf.size(i*m+j);
  }
  vvl dist(n,vl(m));
  queue<ll> dfq;dfq.push(0);
  while(!dfq.empty()){
    ll now=dfq.front();dfq.pop();//探索する輪のid
    vl next;//直下の輪のid
    queue<ll> que;que.push(now);
    dist[now/m][now%m]=1;
    while(!que.empty()){
      ll v=que.front();que.pop();
      ll x=v/m,y=v%m;
      rep(i,4){//輪をすり抜けない
        ll nx=x+dx[i],ny=y+dy[i];
        if(nx<0||ny<0||nx>=n||ny>=m)continue;
        if(dist[nx][ny])continue;
        if(g[nx][ny]=='x'&&uf.root(nx*m+ny)!=now){
          next.push_back(uf.root(nx*m+ny));
        }
        else{
          que.push(nx*m+ny);
          dist[nx][ny]=1;
        }
      }
    }
    sort(all(next));
    next.erase(unique(all(next)),next.end());
    for(auto p:next){
      tr[now].push_back(p);
      dfq.push(p);
    }
  }
  dfs(0);
  cout << max(dp[0][0],dp[0][1]) << endl;
}