#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<cctype>
#include<cstdlib>
#include<algorithm>
#include<bitset>
#include<cstdio>
#include<cstring>
#include<string>
#include<cctype>
#include<cstdlib>
#include<algorithm>
#include<bitset>
#include<vector>
#include<list>
#include<deque>
#include<queue>
#include<map>
#include<set>
#include<stack>
#include<cmath>
#include<sstream>
#include<fstream>
#include<iomanip>
#include<ctime>
#include<complex>
#include<functional>
#include<climits>
#include<cassert>
#include<iterator>
using namespace std;

#define MAX 1012

int n;
int m;

char room[MAX][MAX];

int dx[] = { 1, 1, 0, -1, -1, -1, 0, 1 };
int dy[] = { 0, 1, 1, 1, 0, -1, -1, -1 };


struct st{
	vector < pair<int, int> > v;
};

vector<st> v;

bool use[MAX][MAX];

int deg[MAX*MAX];

int id[MAX][MAX];


bool valid(int x, int y){
	if (x < 0 || y < 0 || x >= n || y >= m){
		return false;
	}
	if (use[x][y]){
		return false;
	}
	if (room[x][y] == '.'){
		return false;
	}
	return true;
}
inline void dfs(int a, int b,int ii){
	use[a][b] = true;
	id[a][b] = ii;
	v[ii].v.push_back(make_pair(a, b));
	for (int i = 0; i < 8; i++){
		if (valid(a + dx[i], b + dy[i])){
			dfs(a + dx[i], b + dy[i],ii);
		}
	}
}

bool done[MAX*MAX];

vector<int> g[MAX*MAX];

bool s[MAX][MAX];

int dxx[] = { 0, 0, 1, -1 };
int dyy[] = { 1, -1, 0, 0 };

bool vv(int a, int b){
	if (a < 0 || b < 0 || a >= n || b >= m){
		return false;
	}
	if (room[a][b] == '.'){
		return true;
	}
	return false;
}
bool v2(int a, int b){
	if (a < 0 || b < 0 || a >= n || b >= m){
		return false;
	}
	return true;
}
vector<int> bfs(int a, int b){
	vector<int> r;
	s[a][b] = true;
	queue<pair<int, int> > q;
	q.push(make_pair(a, b));
	while (!q.empty()){
		a = q.front().first;
		b = q.front().second;
		q.pop();
		for (int i = 0; i < 4; i++){
			int aa = a + dxx[i];
			int bb = b + dyy[i];
			if (vv(aa, bb)){
				if (s[aa][bb] == false){
					s[aa][bb] = true;
					q.push(make_pair(aa, bb));
				}
			}
			else{
				if (v2(aa, bb)){
					r.push_back(id[aa][bb]);
				}
			}
		}
		for (int i = 0; i < 8; i++){
			if (dx[i] == 0 || dy[i] == 0){
				continue;
			}
			if (vv(a + dx[i], b + dy[i])){
				if (v2(a, b + dy[i]) && vv(a, b + dy[i]) == false){
					if (v2(a + dx[i], b) && vv(a + dx[i], b) == false){
						r.push_back(id[a + dx[i]][b]);
						continue;
					}
				}
				if (s[a + dx[i]][b + dy[i]] == false){
					q.push(make_pair(a + dx[i], b + dy[i]));
					s[a + dx[i]][b + dy[i]] = true;
				}
			}
			else{
				if (v2(a + dx[i], b + dy[i])){
					r.push_back(id[a + dx[i]][b + dy[i]]);
				}
			}
		}
	}
	sort(r.begin(), r.end());
	r.erase(unique(r.begin(), r.end()), r.end());
	return r;
}
inline void f(int b){
	done[b] = true;
	set<int> vv;
	for (int i = 0; i < v[b].v.size(); i++){
		for (int j = 0; j < 8; j++){
			int xx = v[b].v[i].first + dx[j];
			int yy = v[b].v[i].second + dy[j];
			if (xx >= 0 && yy >= 0 && xx < n&&yy < m){
				if (room[xx][yy] == '.'){
					if (s[xx][yy] == false){
						vector<int> rr = bfs(xx, yy);
						for (int ii = 0; ii < rr.size(); ii++){
							vv.insert(rr[ii]);
						}
					}
				}
			}
		}
	}
	if (vv.count(b)){
		vv.erase(b);
	}
	for (auto it = vv.begin();it!= vv.end(); it++){
		g[b].push_back((*it));
	}
	vv.clear();
	for (int i = 0; i < g[b].size(); i++){
		f(g[b][i]);
		deg[g[b][i]]++;
	}
}
int dp[MAX*MAX][2];

inline void d(int b){
	dp[b][0] = v[b].v.size();
	for (int i = 0; i < g[b].size(); i++){
		int id = g[b][i];
		d(id);
		dp[b][1] += max(dp[id][0], dp[id][1]);
		dp[b][0] += dp[id][1];
	}
}
int main(){
	cin >> n >> m;
	for (int i = 0; i < n; i++){
		scanf("%s", room[i]);
	}
	for (int i = 0; i < n; i++){
		for (int j = 0; j < m; j++){
			if (valid(i, j)){
				v.push_back(st());
				dfs(i, j, v.size() - 1);
			}
		}
	}
	for (int i = 0; i < n; i++){
		for (int j = 0; j < m; j++){
			if (i == 0 || j == 0 || i == n - 1 || j == m - 1){
				if (room[i][j] == '.'){
					if (s[i][j] == false){
						bfs(i, j);
					}
				}
			}
		}
	}
	for (int i = 0; i < n; i++){
		for (int j = 0; j < m; j++){
			if (room[i][j] == 'x'){
				if (done[id[i][j]] == false){
					f(id[i][j]);
				}
			}
		}
	}
	int ans = 0;
	for (int i = 0; i < v.size(); i++){
		if (deg[i] == 0){
			d(i);
			ans += max(dp[i][0], dp[i][1]);
		}
	}
	cout << ans << endl;
	return 0;
}