n, m = map(int, input().split())
s = [] # 存放迷宫数组
for i in range(n):
    s.append(list(map(int, input().split())))
queue = [(0,0)] * (n * m) # 该队列存放路径上每个点的坐标
d = [[-1] * m for i in range(n)] # 索引代表坐标，存的值代表与起点的距离
d[0][0] = 0

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

def bfs():
    hh, tt = 0, 0
    while hh <= tt:
        x, y = queue[hh]
        hh += 1
        for i in range(4): # 探索(x,y)上下左右四个点
            nx = x + dx[i]
            ny = y + dy[i]
            if nx >= 0 and nx < n and ny >= 0 and ny < m and s[nx][ny] == 0 and d[nx][ny] == -1:
                d[nx][ny] = d[x][y] + 1
                tt += 1
                queue[tt] = (nx, ny)
    return d[n-1][m-1]

print(bfs())