from collections import deque

def bfs():
    dist = [[[-1]*4 for _ in range(W)] for _ in range(H)]
    q = deque([])
    
    if M[0][0]!=M[0][1]:
        dist[0][1][0] = 1
        q.append((0, 1, 0, 0, 0))
    
    if M[0][0]!=M[1][0]:
        dist[1][0][1] = 1
        q.append((1, 0, 0, 0, 1))
        
    while q:
        cx, cy, px, py, f = q.popleft()
        
        for nx, ny, nf in [(cx, cy-1, 0), (cx-1, cy, 1), (cx, cy+1, 2), (cx+1, cy, 3)]:
            if not (0<=nx<H and 0<=ny<W):
                continue
            
            a, b, c = M[nx][ny], M[cx][cy], M[px][py]
            
            if dist[nx][ny][nf]==-1 and a not in [b, c] and ((a>b and b<c) or (a<b and b>c)):
                dist[nx][ny][nf] = dist[cx][cy][f]+1
                q.append((nx, ny, cx, cy, nf))
    
    return dist

W, H = map(int, input().split())
M = [list(map(int, input().split())) for _ in range(H)]
dist = bfs()
ans = 10**18

for i in range(4):
    if dist[H-1][W-1][i]==-1:
        continue
    
    ans = min(ans, dist[H-1][W-1][i])

if ans==10**18:
    print(-1)
else:
    print(ans)