class UnionFind:
    def __init__(self, n):
        self.parent = list(range(n)) #親ノード
        self.size = [1]*n #グループの要素数
 
    def root(self, x): #root(x): xの根ノードを返す．
        while self.parent[x] != x:
            self.parent[x] = self.parent[self.parent[x]]
            x = self.parent[x]
        return x 
 
    def merge(self, x, y): #merge(x,y): xのいる組とyのいる組をまとめる
        x, y = self.root(x), self.root(y)
        if x == y: return False
        if self.size[x] < self.size[y]: x,y=y,x #xの要素数が大きいように
        self.size[x] += self.size[y] #xの要素数を更新
        self.parent[y] = x #yをxにつなぐ
        return True
 
    def issame(self, x, y): #same(x,y): xとyが同じ組ならTrue
        return self.root(x) == self.root(y)
        
    def getsize(self,x): #size(x): xのいるグループの要素数を返す
        return self.size[self.root(x)]

n,m = map(int,input().split())
b = ["."*(m+2)]
for i in range(n):
    b.append("."+input()+".")
b.append("."*(m+2))
n += 2
m += 2
N = n*m
UF = UnionFind(N+1)
for i in range(n):
    for j in range(m):
        if b[i][j] == "x":
            for ni,nj in [(i-1,j-1),(i-1,j),(i-1,j+1),(i,j-1)]:
                if 0 <= ni < n and 0 <= nj < m and b[ni][nj] == "x":
                    UF.merge(i*m+j,ni*m+nj)

def dfs(X):
    q = [X]
    outer = N
    inner = set()
    while q:
        x = q.pop()
        i,j = x//m, x%m
        for ni,nj in [(i-1,j),(i+1,j),(i,j-1),(i,j+1)]:
            nx = ni*m+nj
            if 0 <= ni < n and 0 <= nj < m:
                if b[ni][nj] == ".":
                    if used[nx]==0:
                        used[nx] = 1
                        q.append(nx)
                else:
                    nr = UF.root(nx)
                    if nr in parent:
                        outer = nr
                    else:
                        inner.add(nr)
    for x in inner:
        parent[x] = outer

used = [0]*N
parent = {N:-1}
for i in range(n):
    for j in range(m):
        x = i*m+j
        if used[x]==0 and b[i][j] == ".":
            used[x] = 1
            dfs(x)

P = list(parent.keys())
dpnot = {i:0 for i in P}
dpuse = {i:UF.getsize(i) for i in P}
dpuse[N] = 0
dpuse[-1] = dpnot[-1] = 0
for v in P[::-1]:
    p = parent[v]
    dpuse[p] += dpnot[v]
    dpnot[p] += max(dpuse[v],dpnot[v])

print(max(dpuse[N],dpnot[N]))