#include <bits/stdc++.h>
#define INF INT_MAX / 2
#define MOD 1000000007

using namespace std;

typedef pair<int,int> PII;
typedef pair<int,pair<int,int>> PIPII;
typedef long long ll;

bool isKadomatsuSequence(int a2,int a1,int a0){
	if((a1 < a0 && a1 < a2 || a1 > a2 && a1 > a0) && a2 != a0)return true;
	return false;
}

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

int m[101][101];
bool used[101][101];
int memo[101][101][11][11];

int w,h;
int dfs(int y,int x,int prev2,int prev1){
	if(y<0||y>=h||x<0||x>=w|| prev2 != -1 && !isKadomatsuSequence(prev2,prev1,m[y][x]) || used[y][x])return INF;
	if(y == h-1 && x == w-1)return 0;
	if(memo[y][x][prev2+1][prev1+1] != -1)return memo[y][x][prev2+1][prev1+1];
	//cout << y << " " << x << endl;
	int ret = INF;
	for(int i=0;i<4;i++){
		used[y][x] = true;
		ret = min(ret,dfs(y+dy[i],x+dx[i],prev1,m[y][x]));
		used[y][x] = false;
	}
	return memo[y][x][prev2+1][prev1+1] = ret+1;
}

int main(void) {
	cin >> w >> h;
	memset(memo,-1,sizeof(memo));
	for(int i=0;i<h;i++){
		for(int j=0;j<w;j++){
			cin >> m[i][j];
		}
	}
	int ans = dfs(0,0,-1,-1);
	if(ans>=INF)cout << -1 << endl;
	else cout << ans << endl;
}