#include <iostream>
#include <cstdio>
#include <string>
#include <sstream>
#include <algorithm>
#include <math.h>
#include <map>
#include <iomanip>
#include <vector>
#include <queue>
#include <set>
#define PI 3.14159265359
#define INF 99999999;
#define rep(i, n) for(int i=0; i<n; i++)
#define REP(n) rep(i, n)
#define EPS 1e-10
typedef long long ll;
using namespace std;



/*
class Target
{
public:
	vector <string> draw(int n)
	{

	}
};
*/


class Pos
{
public:
	//書かれている数字
	int num;
	int x, y, cnt;
	int pre;
	
	Pos(int pnum, int px, int py, int pcnt, int ppre)
	{
		num = pnum;
		x = px;
		y = py;
		cnt = pcnt;
		pre = ppre;
	}
	
};

int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};


int main()
{
	int W, H, M[100][100];
	bool bM[110][110] = {false};
	
	cin >> W >> H;
	rep(i, H) rep(j, W) cin >> M[i][j];
	bool flag = false;
	
	queue<Pos> q;
	q.push(Pos(M[0][0], 0, 0, 0, 0));
	q.push(Pos(M[0][0], 0, 0, 0, 10));
	bM[0][0] = true;
	while (!q.empty())
	{
		Pos now = q.front();
		q.pop();
		if (now.x == W - 1 && now.y == H - 1)
		{
			cout << now.cnt << endl;
			flag = true;
			break;
		}
		for (int i=0; i<4; i++)
		{
			int nx = now.x + dx[i];
			int ny = now.y + dy[i];
			if (0<=nx && nx<W && 0<=ny && ny<H && M[ny][nx] != now.pre && !bM[ny][nx])
			{
				if (now.pre < now.num)
				{
					if (M[ny][nx] < now.num)
					{
						Pos next = Pos(M[ny][nx], nx, ny, now.cnt + 1, now.num);
						bM[ny][nx] = true;
						q.push(next);
					}
				} else {
					if (M[ny][nx] > now.num)
					{
						Pos next = Pos(M[ny][nx], nx, ny, now.cnt + 1, now.num);
						bM[ny][nx] = true;
						q.push(next);
					}
				}
			}
		}
	}
	
	if (!flag)
	{
		cout << -1 << endl;
	}
	return 0;
}