W,H = map(int,input().split())
M = [list(map(int,input().split())) for _ in range(H)]
dir = [[0,1],[1,0],[-1,0],[0,-1]]
INF = 10 ** 3
def dfs(a):
    Q = [(0,0,-1)]
    Q2 = []
    cnt = 0
    while Q:
        while Q:
            x,y,z = Q.pop()
            if x == H-1 and y == W - 1:
                return cnt
            v = M[x][y]
            for dx,dy in dir:
                x2 = x + dx
                y2 = y + dy
                if 0 <= x2 < H and 0 <= y2 < W:
                    if a == 1:
                        if v > M[x2][y2] and M[x2][y2] != z:
                            Q2.append((x2,y2,M[x][y]))
                    else:
                        if v < M[x2][y2] and M[x2][y2] != z:
                            Q2.append((x2,y2,M[x][y]))
        a ^= 1
        cnt += 1
        Q,Q2 = Q2,Q
    return INF

a = min(dfs(0),dfs(1))
if a == INF:
    print(-1)
else:
    print(a)