# BFS distanceをやろうかと思ったがH, W小さい
# それぞれの空洞の座標をリストアウト
# 全探索して最小マンハッタン距離でいいか
# 空洞1と空洞2を決めるにはUnion Find使うか

class UnionFind():
    def __init__(self, n):
        self.n = n
        self.parents = [-1] * n

    def find(self, x):
        if self.parents[x] < 0:
            return x
        else:
            self.parents[x] = self.find(self.parents[x])
            return self.parents[x]

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)

        if x == y:
            return

        if self.parents[x] > self.parents[y]:
            x, y = y, x

        self.parents[x] += self.parents[y]
        self.parents[y] = x

    def size(self, x):
        return -self.parents[self.find(x)]

    def same(self, x, y):
        return self.find(x) == self.find(y)

    def members(self, x):
        root = self.find(x)
        return [i for i in range(self.n) if self.find(i) == root]

    def roots(self):
        return [i for i, x in enumerate(self.parents) if x < 0]

    def group_count(self):
        return len(self.roots())

    def all_group_members(self):
        group_members = defaultdict(list)
        for member in range(self.n):
            group_members[self.find(member)].append(member)
        return group_members

    def __str__(self):
        return '\n'.join(f'{r}: {m}' for r, m in self.all_group_members().items())

W, H = map(int, input().split())
C = []
for i in range(H):
    C.append(input())

UF = UnionFind(W*H)
for i in range(H):
    for j in range(W):
        if j<W-1 and C[i][j] == '.' and C[i][j+1] == '.':
            UF.union(i*W+j, i*W+j+1)
        if i<H-1 and C[i][j] == '.' and C[i+1][j] == '.':
            UF.union(i*W+j, (i+1)*W+j)            

from collections import defaultdict
#print(UF.all_group_members())

groups = []
for root in UF.roots():
    if C[root//W][root%W] == '.':
        groups.append(UF.members(root))

#print(groups)

ans = 10**5
for g0 in groups[0]:
    for g1 in groups[1]:
        calc = abs(g0//W-g1//W)+abs(g0%W-g1%W)-1
        ans = min(ans, calc)
print(ans)