from collections import deque
import sys
import copy

N, M = map(int, sys.stdin.readline().split())
arr = [[0]]
visit = [[0 for j in range(1001)]for i in range(1001)]
storage = [] # 경로값 저장
for i in range(N):
    arr.append([0]+list(sys.stdin.readline()))
def findroute(): # 0인 곳만을 찾아가는 함수..
    visit2 = copy.deepcopy(visit)
    visit2[1][1] = 1
    q = deque()
    q.append((1, 1))
    while q:
        x, y = q.popleft()
        if x == N and y == M:
            storage.append(visit2[N][M])
            break
        if x - 1 >= 1:
            if arr[x - 1][y] == 0 and visit2[x-1][y] == 0:
                q.append((x - 1, y))
                visit2[x - 1][y] = visit2[x][y] + 1
        if x + 1 <= 1000:
            if arr[x + 1][y] == 0 and visit2[x+1][y] == 0:
                q.append((x + 1, y))
                visit2[x + 1][y] = visit2[x][y] + 1
        if y - 1 >= 1:
            if arr[x][y - 1] == 0 and visit2[x][y-1] == 0:
                q.append((x, y - 1))
                visit2[x][y - 1] = visit2[x][y] + 1
        if y + 1 <= 1000:
            if arr[x][y + 1] == 0 and visit2[x][y+1] == 0:
                q.append((x, y + 1))
                visit2[x][y + 1] = visit2[x][y] + 1

for i in range(1, N+1):
    for j in range(1, M+1):
        if arr[i][j] == 1:
            arr[i][j] = 0
            findroute()
            arr[i][j] = 1
print(storage)