#!/usr/bin/env python


def read():
    col, row = map(int, raw_input().split())
    b = []
    for i in range(row):
        b.append(map(int, raw_input().split()))
    return row, col, b


def isKadomatsu(a, b, c):
    if a == 0 or b == 0:
        return True
    return b > a > c or b > c > a or a > c > b or c > a > b


def work((row, col, b)):
    # cost[r][c][A_0][A_1]: # of step
    cost = [[[[-1 for l in range(10)] for k in range(10)] for j in range(col)] for i in range(row)]
    Q = []
    
    cost[0][0][0][b[0][0]] = 0
    Q.append((0, 0, 0, b[0][0]))

    while Q:
        (r, c, A0, A1) = Q[0]
        del Q[0]

        if r == row - 1 and c == col - 1:
            print cost[r][c][A0][A1]
            return

        for (dr, dc) in [(-1, 0), (0, 1), (1, 0), (0, -1)]:
            nr = r + dr
            nc = c + dc
            if not (0 <= nr < row and 0 <= nc < col):
                continue
            if not isKadomatsu(A0, A1, b[nr][nc]):
                continue
            if cost[nr][nc][A1][b[nr][nc]] != -1:
                continue
            cost[nr][nc][A1][b[nr][nc]] = cost[r][c][A0][A1] + 1
            Q.append((nr, nc, A1, b[nr][nc]))

    print -1

    
if __name__ == "__main__":
    work(read())