using System; using System.IO; using System.Linq; using System.Text; using System.Collections.Generic; using System.Diagnostics; using System.Numerics; using Enu = System.Linq.Enumerable; using System.Text.RegularExpressions; class Program { public void Solve() { int H = Reader.Int(), W = Reader.Int(); var grid = Reader.StringArray(H); var uf = new UnionFind(H * W); var circleDic = new Dictionary(); Func IsInside = (y, x) => y >= 0 && y < H && x >= 0 && x < W; for (int y = 0; y < H; y++) for (int x = 0; x < W; x++) if (grid[y][x] == 'x') for (int dy = -1; dy <= 1; dy++) for (int dx = -1; dx <= 1; dx++) { if (dy == 0 && dx == 0) continue; int ny = y + dy, nx = x + dx; if (IsInside(ny, nx) && grid[ny][nx] == 'x') uf.Unite(y * W + x, ny * W + nx); } for (int y = 0; y < H; y++) for (int x = 0; x < W; x++) if (grid[y][x] == 'x') { int id = uf.Root(y * W + x); if (uf.NumElements(id) < 3) continue; if (!circleDic.ContainsKey(id)) circleDic[id] = new Circle(id); circleDic[id].UpdateY(y); circleDic[id].UpdateX(x); } var circles = circleDic.Values.ToArray(); var numElements = circles.Select(c => uf.NumElements(c.Id)).ToArray(); int N = circles.Length; var parent = Enu.Repeat(-1, N).ToArray(); var G = CheckChild(circles, N, parent); memo = new int?[N, 2]; int ans = 0; for (int i = 0; i < N; i++) if (parent[i] == -1) ans += Rec(i, 1, numElements, G); Console.WriteLine(ans); } private int[][] CheckChild(Circle[] circles, int N, int[] parent) { const int Big = 10000, Div = 30; var bucket = new Dictionary>(); for (int i = 0; i < N; i++) { int id = circles[i].X1 / Div * Big + circles[i].Y1 / Div; if (!bucket.ContainsKey(id)) bucket[id] = new List(); bucket[id].Add(i); } for (int a = 0; a < N; a++) { int x = circles[a].X1 / Div; int y = circles[a].Y1 / Div; for (; x <= circles[a].X2 / Div; x++) for (; y <= circles[a].Y2 / Div; y++) { int id = x * Big + y; if (!bucket.ContainsKey(id)) continue; foreach (int b in bucket[id]) if (circles[b].IsInside(circles[a]) && (parent[b] == -1 || circles[a].IsInside(circles[parent[b]]))) parent[b] = a; } } var G = Enu.Range(0, N).Select(i => new List()).ToArray(); for (int i = 0; i < N; i++) if (parent[i] != -1) G[parent[i]].Add(i); return G.Select(g => g.ToArray()).ToArray(); } int?[,] memo; private int Rec(int i, int canUse, int[] numElements, int[][] G) { if (memo[i, canUse].HasValue) return memo[i, canUse].Value; int res = 0; foreach (int child in G[i]) res += Rec(child, 1, numElements, G); if (canUse == 1) { int use = numElements[i]; foreach (int child in G[i]) use += Rec(child, 0, numElements, G); res = Math.Max(res, use); } memo[i, canUse] = res; return res; } class Circle { public int Id; public int X1 = int.MaxValue, X2 = int.MinValue; public int Y1 = int.MaxValue, Y2 = int.MinValue; public Circle(int id) { Id = id; } public void UpdateX(int x) { X1 = Math.Min(X1, x); X2 = Math.Max(X2, x); } public void UpdateY(int y) { Y1 = Math.Min(Y1, y); Y2 = Math.Max(Y2, y); } public bool IsInside(Circle b) { return X1 > b.X1 && X2 < b.X2 && Y1 > b.Y1 && Y2 < b.Y2; } } class UnionFind { private int[] parent; private int[] rank; private int[] numElements; public UnionFind(int N) { parent = new int[N]; rank = new int[N]; numElements = new int[N]; for (int i = 0; i < N; i++) { parent[i] = i; numElements[i] = 1; } } public int Root(int x) { if (parent[x] == x) return x; return parent[x] = Root(parent[x]); } public bool Same(int x, int y) { return Root(x) == Root(y); } public int NumElements(int x) { return numElements[Root(x)]; } public bool Unite(int x, int y) { x = Root(x); y = Root(y); if (x == y) return false; if (rank[x] > rank[y]) { var t = x; x = y; y = t; } if (rank[x] == rank[y]) rank[y]++; parent[x] = y; numElements[y] += numElements[x]; return true; } public int[][] Components() { var dic = new Dictionary>(); for (int i = 0; i < parent.Length; i++) { int root = Root(i); if (!dic.ContainsKey(root)) dic[root] = new List(); dic[root].Add(i); } return dic.Values.Select(c => c.ToArray()).ToArray(); } } } class Entry { static void Main() { new Program().Solve(); } } class Reader { private static TextReader reader = Console.In; private static readonly char[] separator = { ' ' }; private static readonly StringSplitOptions op = StringSplitOptions.RemoveEmptyEntries; private static string[] A = new string[0]; private static int i; private static void Init() { A = new string[0]; } public static void Set(TextReader r) { reader = r; Init(); } public static void Set(string file) { reader = new StreamReader(file); Init(); } public static bool HasNext() { return CheckNext(); } public static string String() { return Next(); } public static int Int() { return int.Parse(Next()); } public static long Long() { return long.Parse(Next()); } public static double Double() { return double.Parse(Next()); } public static int[] IntLine() { return Array.ConvertAll(Split(Line()), int.Parse); } public static int[] IntArray(int N) { return Enu.Range(0, N).Select(i => Int()).ToArray(); } public static int[][] IntTable(int H) { return Enu.Range(0, H).Select(i => IntLine()).ToArray(); } public static string[] StringArray(int N) { return Enu.Range(0, N).Select(i => Next()).ToArray(); } public static string Line() { return reader.ReadLine().Trim(); } private static string[] Split(string s) { return s.Split(separator, op); } private static string Next() { CheckNext(); return A[i++]; } private static bool CheckNext() { if (i < A.Length) return true; string line = reader.ReadLine(); if (line == null) return false; if (line == "") return CheckNext(); A = Split(line); i = 0; return true; } }