import collections

import sys

n, m = map(int, sys.stdin.readline().split())

graph = [list(map(int, sys.stdin.readline().rstrip())) for _ in range(n)]

visited = [[[0]*2 for _ in range(m)] for _ in range(n)]

dx = [-1, 0, 1, 0]

dy = [0, 1, 0, -1]

def bfs():

dq = collections.deque()

dq.append([0, 0, 0])

visited[0][0][0] = 1

while dq:

y, x, crash = dq.popleft()

if y == n-1 and x == m-1:

return visited[y][x][crash]

for i in range(4):

ny = y + dy[i]

nx = x + dx[i]

if ny < 0 or ny >= n or nx < 0 or nx >= m:

continue

if graph[ny][nx] == 0 and visited[ny][nx][crash] == 0:

dq.append([ny, nx, crash])

visited[ny][nx][crash] = visited[y][x][crash]+1

if graph[ny][nx] == 1 and crash == 0:

visited[ny][nx][crash+1] = visited[y][x][crash]+1

dq.append([ny,nx,crash+1])

return -1

print(bfs())