from collections import deque

def bfs(sx, sy):
    queue = deque([])
    queue.append((sx, sy))
    visited = [[-1 for _ in range(W)] for _ in range(H)]
    visited[sx][sy] = 1
    
    while len(queue) > 0:
        current_x, current_y = queue.popleft()
        for next_x, next_y in [(current_x-1, current_y), (current_x+1, current_y), (current_x, current_y-1), (current_x, current_y+1)]:
            if 0 <= next_x < H and 0 <= next_y < W:
                if C[next_x][next_y] == '.' and visited[next_x][next_y] == -1:
                    visited[next_x][next_y] = 1
                    queue.append((next_x, next_y))
    
    return visited

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

for i in range(H):
    for j in range(W):
        if C[i][j] == '.':
            amx, amy = i, j
            break

visitedA = bfs(amx, amy)
holeA = []

for i in range(H):
    for j in range(W):
        if visitedA[i][j] == 1:
            holeA.append((i, j))

for i in range(H):
    for j in range(W):
        if C[i][j] == '.' and visitedA[i][j] == -1:
            bmx, bmy = i, j
            break

visitedB = bfs(bmx, bmy)
holeB = []

for i in range(H):
    for j in range(W):
        if visitedB[i][j] == 1:
            holeB.append((i, j))

ans = 10 ** 18

for Ax, Ay in holeA:
    for Bx, By in holeB:
        ans = min(ans, abs(Ax-Bx) + abs(Ay-By) - 1)

print(ans)