import Queue

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

color = [[0 for _ in xrange(W)] for _ in xrange(H)]

currentColor = 1

for i in xrange(H):
	for j in xrange(W):
		if C[i][j] != '#' and color[i][j] == 0:
			q = Queue.Queue()
			q.put((i, j))
			color[i][j] = currentColor
			while not q.empty():
				y, x = q.get()
				for dy, dx in [(0, 1), (1, 0), (0, -1), (-1, 0)]:
					ny = y + dy
					nx = x + dx
					if ny < 0 or ny >= H or nx < 0 or nx >= W: continue
					if C[ny][nx] == '#': continue
					if color[ny][nx] != 0: continue
					color[ny][nx] = currentColor
					q.put((ny, nx))
			currentColor += 1

sy, sx, gy, gx = 0, 0, 0, 0
for i in xrange(H):
	for j in xrange(W):
		if color[i][j] == 1:
			sy, sx = i, j
		elif color[i][j] == 2:
			gy, gx = i, j

inf = 10 ** 10
dist = [[inf for _ in xrange(W)] for _ in xrange(H)]

dist[sy][sx] = 0
q = Queue.PriorityQueue()
q.put((0, sy, sx))

while not q.empty():
	_, y, x = q.get()
	for dy, dx in [(1, 0), (0, 1), (-1, 0), (0, -1)]:
		ny = y + dy
		nx = x + dx
		if ny < 0 or ny >= H or nx < 0 or nx >= W: continue
		if color[ny][nx] == 0:
			cost = 1
		else:
			cost = 0
		if dist[ny][nx] > dist[y][x] + cost:
			dist[ny][nx] = dist[y][x] + cost
			q.put((dist[ny][nx], ny, nx))

print dist[gy][gx]