#10#12哇了，为什么

#include <bits/stdc++.h>
#define mian main
using namespace std;

int a[10][10],n,m;
int vis[10][10];
int dx[4] = {0,0,1,-1};
int dy[4] = {-1,1,0,0};
int ans = 1e9;

struct Node {
	int x,y,hp,step;
};

queue<Node> q;

void bfs() {
	while(!q.empty()) {
		Node nw = q.front();
		q.pop();
		int x = nw.x,y = nw.y,hp = nw.hp,step = nw.step;
		vis[x][y] = 1;
		if(hp == 0) continue;
		if(a[x][y] == 3) ans = min(ans,step);
		if(a[x][y] == 4) hp = 6;
		for(int i = 0; i < 4; i++) {
			int nx = x + dx[i];
			int ny = y + dy[i];
			if(nx < 1 || nx > n || ny < 1 || ny > m || vis[nx][ny]) continue;
 			if(a[nx][ny] == 0) continue;
 			q.push({nx,ny,hp-1,step+1});
		}
	}
}

int mian() {
	cin >> n >> m;
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= m; j++) {
			cin >> a[i][j];
			if(a[i][j] == 2) q.push({i,j,6,0});
		}
	}
	bfs();
	if(ans == 1e9) cout << -1;
	else cout << ans;
  	return 0;
}