package contest;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

public class Q795 {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int n = ni(), m = ni();
		char[][] map = nm(n,m);
		char[][] nmap = new char[n+2][m+2];
		for(int i = 0;i < n+2;i++)Arrays.fill(nmap[i], '.');
		for(int i = 0;i < n;i++){
			for(int j = 0;j < m;j++){
				nmap[i+1][j+1] = map[i][j];
			}
		}
		map = nmap;
		n += 2; m += 2;
		
		DJSet ds = new DJSet(n*m);
		for(int i = 0;i < n;i++){
			for(int j = 0;j < m-1;j++){
				if(map[i][j] == '.' && map[i][j+1] == '.'){
					ds.union(i*m+j, i*m+j+1);
				}
			}
		}
		for(int i = 0;i < n-1;i++){
			for(int j = 0;j < m;j++){
				if(map[i][j] == '.' && map[i+1][j] == '.'){
					ds.union(i*m+j, (i+1)*m+j);
				}
			}
		}
		for(int i = 0;i < n;i++){
			for(int j = 0;j < m;j++){
				for(int k = i-1;k <= i+1;k++){
					for(int l = j-1;l <= j+1;l++){
						if(k >= 0 && k < n && l >= 0 && l < m && map[i][j] == 'x' && map[k][l] == 'x'){
							ds.union(i*m+j, k*m+l);
						}
					}
				}
			}
		}
		
		int z = ds.count();
		boolean[][] g = new boolean[z][z];
		int[] ind = new int[n*m];
		int[] iind = new int[n*m];
		int[] size = new int[n*m];
		Arrays.fill(ind, -1);
		int p = 0;
		for(int i = 0;i < n*m;i++){
			if(ds.upper[i] < 0){
				ind[i] = p;
				iind[p] = i;
				size[p] = -ds.upper[i];
				p++;
			}
		}
		
		int[] dr = { 1, 0, -1, 0 };
		int[] dc = { 0, 1, 0, -1 };
		for(int i = 0;i < n;i++){
			for(int j = 0;j < m;j++){
				if(map[i][j] == '.'){
					for(int k = 0;k < 4;k++){
						int nr = i + dr[k], nc = j + dc[k];
						if(nr >= 0 && nr < n && nc >= 0 && nc < m && map[nr][nc] == 'x'){
							g[ind[ds.root(i*m+j)]][ind[ds.root(nr*m+nc)]] = true;
							g[ind[ds.root(nr*m+nc)]][ind[ds.root(i*m+j)]] = true;
						}
					}
				}
			}
		}
		int root = ind[ds.root(0)];
//		tf(g);
		int[] res = dfs(root, -1, g, iind, size);
		out.println(Math.max(res[0], res[1]));
	}
	
	public static void tf(boolean[][] b) {
		for (boolean[] r : b) {
			char[] s = new char[r.length];
			for (int i = 0; i < r.length; i++)
				s[i] = r[i] ? '#' : '.';
			System.out.println(new String(s));
		}
		System.out.println();
	}
	
	static int[] dfs(int cur, int pre, boolean[][] g, int[] iind, int[] size)
	{
		int n = g.length;
		int r1 = 0;
		int r0 = 0;
		for(int i = 0;i < n;i++){
			if(g[cur][i] && i != pre){
				int v = 0, w = 0;
				int ap = 0;
				for(int j = 0;j < n;j++){
					if(g[i][j] && j != cur){
						int[] res = dfs(j, i, g, iind, size);
						v = Math.max(v, res[1]);
						v = Math.max(v, res[0] + size[i]);
						w = Math.max(w, res[1]);
						w = Math.max(w, res[0]);
						if(++ap > 1)throw new RuntimeException();
					}
				}
				r1 += v;
				r0 += w;
				if(ap == 0){
					r1 += size[i];
				}
			}
		}
		return new int[]{r0, r1};
	}
	
	public static class DJSet {
		public int[] upper;

		public DJSet(int n) {
			upper = new int[n];
			Arrays.fill(upper, -1);
		}

		public int root(int x) {
			return upper[x] < 0 ? x : (upper[x] = root(upper[x]));
		}

		public boolean equiv(int x, int y) {
			return root(x) == root(y);
		}

		public boolean union(int x, int y) {
			x = root(x);
			y = root(y);
			if (x != y) {
				if (upper[y] < upper[x]) {
					int d = x;
					x = y;
					y = d;
				}
				upper[x] += upper[y];
				upper[y] = x;
			}
			return x == y;
		}

		public int count() {
			int ct = 0;
			for (int u : upper)
				if (u < 0)
					ct++;
			return ct;
		}
	}
	
	void run() throws Exception
	{
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);
		
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
	}
	
	public static void main(String[] args) throws Exception { new Q795().run(); }
	
	private byte[] inbuf = new byte[1024];
	private int lenbuf = 0, ptrbuf = 0;
	
	private int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}
	
	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private double nd() { return Double.parseDouble(ns()); }
	private char nc() { return (char)skip(); }
	
	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
	
	private char[][] nm(int n, int m)
	{
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}
	
	private int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private int ni()
	{
		int num = 0, b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }
}