#include <cstdio>
#include <iostream>
#include <vector>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <string>
#include <cstring>
#include <sstream>
#include <algorithm>
#include <functional>
#include <queue>
#include <stack>
#include <cmath>
#include <iomanip>
#include <list>
#include <tuple>
#include <bitset>
#include <ciso646>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> P;
typedef tuple<ll, ll, ll> T;
typedef vector<ll> vec;

inline bool cheak(ll x, ll y, ll xMax, ll yMax) { return x >= 0 && y >= 0 && xMax > x && yMax > y; }
inline int toint(string s) { int v; istringstream sin(s); sin >> v; return v; }
template<class T> inline string tostring(T x) { ostringstream sout; sout << x; return sout.str(); }
template<class T> inline T sqr(T x) { return x*x; }
template<class T> inline T mypow(T x, ll n) { T res = 1; while (n > 0) { if (n & 1)res = res * x;	x = x * x;	n >>= 1; }return res; }
inline int gcd(ll a, ll b) { return b ? gcd(b, a%b) : a; }
inline int lcm(ll a, ll b) { return a / gcd(a, b) * b; }

#define For(i,a,b)	for(ll (i) = (a);i < (b);(i)++)
#define rep(i,n)	For(i,0,n)
#define rFor(i,a,b)	for(ll (i) = (a-1);i >= (b);(i)--)
#define rrep(i,n)	rFor(i,n,0)
#define each(i,n)	for(auto &i : n)
#define clr(a)		memset((a), 0 ,sizeof(a))
#define mclr(a)		memset((a), -1 ,sizeof(a))
#define all(a)		(a).begin(),(a).end()
#define sz(a)		(sizeof(a))
#define tostr(a)	tostring(a)
#define dump(val) 	cerr << #val " = " << val << endl;
#define Fill(a,v)	fill((int*)a,(int*)(a+(sz(a)/sz(*(a)))),v)

const ll dx[8] = { 1, 0, -1, 0, 1, 1, -1, -1 }, dy[8] = { 0, -1, 0, 1, -1, 1, -1, 1 };

const ll mod = 1e9 + 7;
const ll INF = 1e17 + 9;

#define int ll
#define double ld

signed main() {
	cin.tie(0);
	ios_base::sync_with_stdio(false);

	int h, w;
	cin >> h >> w;
	vector<string> d;
	d.push_back(string(w + 2, '.'));
	rep(y, h) {
		string s;
		cin >> s;
		d.push_back(s);
		d[d.size()-1] = "." + d[d.size()-1] + ".";
	}
	d.push_back(string(w + 2, '.'));
	w += 2, h += 2;

	auto dump_d = [&]() {
		rep(y, h) {
			rep(x, w) {
				cerr << d[y][x];
			}
			cerr << endl;
		}
		cerr << endl;
	};

	vector<int> size;
	size.push_back(0);
	vector<vector<int>> to;
	to.push_back(vector<int>());

	function<int(int, int)> xsize = [&](int y, int x) {
		int ret = 1;
		d[y][x] = 'o';
		for (int dir = 0; dir < 8; dir++) {
			int tx = x + dx[dir], ty = y + dy[dir];
			if (cheak(tx, ty, w, h) && d[ty][tx] == 'x') {
				ret += xsize(ty, tx);
			}
		}
		return ret;
	};

	function<void(int, int, int)> dfs = [&](int i, int sy, int sx) {

		function<void(int, int)> dfs3 = [&](int y, int x) {
			d[y][x] = '1';
			rep(dir, 4) {
				int tx = x + dx[dir], ty = y + dy[dir];
				if (cheak(tx, ty, w, h) && d[ty][tx] == '.') {
					dfs3(ty, tx);
				}
			}
		};
		dfs3(sy, sx);

		function<void(int, int)> dfs2 = [&](int y, int x) {
			if (d[y][x] == 'x') {
				int j = size.size();
				size.push_back(xsize(y, x));
				to[i].push_back(j);
				to.push_back(vector<int>());

				rep(dir, 8) {
					int tx = x + dx[dir], ty = y + dy[dir];
					if (cheak(tx, ty, w, h) && d[ty][tx] == '.') {
						dfs(j, ty, tx);
						break;
					}
				}
			}
			else {
				d[y][x] = 'o';
				rep(dir, 4) {
					int tx = x + dx[dir], ty = y + dy[dir];
					if (cheak(tx, ty, w, h) && d[ty][tx] != 'o') {
						dfs2(ty, tx);
					}
				}
			}
		};

		dfs2(sy, sx);
	};
	dfs(0, 0, 0);

	vector<vector<int>> dp(size.size(), vector<int>(2, -1));
	function<int(int, bool)> solve = [&](int i, bool use) {
		if (dp[i][use] != -1)return dp[i][use];
		int ret = 0;
		int tmp0 = 0, tmp1 = 0;
		rep(j, to[i].size()) {
			tmp0 += solve(to[i][j], true);
			tmp1 += solve(to[i][j], false);
		}
		if (use) {
			return dp[i][use] = size[i] + tmp1;
		}
		else {
			return dp[i][use] = max(tmp0, tmp1);
		}
	};

	cout << solve(0, false) << endl;

	return 0;
}