import java.math.*;
import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int column = sc.nextInt();
        int row = sc.nextInt();
        int[][] maze = new int[row][column];
        int[] vx = {0,1,0,-1};
        int[] vy={-1,0,1,0};
        int[][] fromx = new int[row][column];
        int[][] fromy = new int[row][column];
        int[][] kai = new int[row][column];
        for(int i=0;i<row;i++){
        	for(int j=0;j<column;j++){
        		maze[i][j]=sc.nextInt();
        	}
        }
        Queue<Integer> quex = new LinkedList<Integer>();
        Queue<Integer> quey = new LinkedList<Integer>();
        Queue<Integer> moto = new LinkedList<Integer>();
        Queue<Integer> hoo = new LinkedList<Integer>();
        quex.offer(1);
        quey.offer(0);
        quex.offer(0);
        quey.offer(1);
        hoo.offer(1);
        hoo.offer(1);
        moto.offer(maze[0][0]);
        moto.offer(maze[0][0]);
        while(!quex.isEmpty()){
        	int nx = quex.poll();
        	int ny = quey.poll();
        	int nowho = hoo.poll();
        	int moto1 = moto.poll();
        	for(int i=0;i<4;i++){
        		int nex = nx+vx[i];
        		int ney = ny+vy[i];
        		if(nex<0 || nex > column-1 || ney<0 || ney > row-1) continue;
        		if( ((moto1 > maze[ny][nx] && maze[ney][nex]>maze[ny][nx]) || (moto1 < maze[ny][nx] && maze[ney][nex]<maze[ny][nx]))&&kai[ney][nex]<4 && (fromx[ney][nex]!=nx||fromy[ney][nex]!=ny)&&moto1!=maze[ny][nx]&&moto1 != maze[ney][nex] && maze[ny][nx]!=maze[ney][nex]){
        			quex.offer(nex);
        			quey.offer(ney);
        			moto.offer(maze[ny][nx]);
        			hoo.offer(nowho+1);
        			fromx[ney][nex]=nx;
        			fromy[ney][nex]=ny;
        			kai[ney][nex]++;
        			if(nex == column-1 && ney == row-1){
                		System.out.println(nowho+1);
                		return;
                	}
        		}
        	}
        }
        System.out.println(-1);
    }
}