#include <iostream>
#include <memory>
#include <memory.h>
#include <cmath>
#include <fstream>
#include <cmath>
#include <numeric>
#include <vector>
#include <stack>
#include <string>
#include <queue>
#include <sstream>
#include <cstdlib>
#include <cassert>
#include <cstdio>
#include <map>
#include <iomanip>
#include <list>
#include <cctype>
#include <algorithm>
#include <complex>
#define USE_MATH_DEFINES
using namespace std;

typedef complex<double> xy_t;
typedef pair<xy_t, xy_t> line;
typedef long long ll;
typedef pair<int, int> P;
typedef pair<int, P> PP;
typedef pair<int, PP> PPP;
const int INF = 1 << 29;
const double EPS = 1E-10;

namespace std{
	bool operator < (const xy_t &a, const xy_t &b){
		return real(a) != real(b) ? real(a) < real(b) : imag(a) < imag(b);
	}
}

double cross(const xy_t &a, const xy_t &b){
	return imag(conj(a) * b);
}

double dot(const xy_t &a, const xy_t &b){
	return real(conj(a)*b);
}

xy_t projection(const line &l, const xy_t &p){
	double t = dot(l.second - l.first, p - l.first) / norm(l.second - l.first);
	return l.first + t * (l.second - l.first);
}

int ccw(xy_t a, xy_t b, xy_t c){
	b -= a; c -= a;
	if(cross(b, c) > 0) return 1;
	if(cross(b, c) < 0) return -1;
	if(dot(b, c) < 0) return +2;
	if(norm(b) < norm(c) ) return -2;
	return 0;
}

bool intersectSP(const line &s, const xy_t &p){
	return abs(s.first - p) + abs(s.second - p) - abs(s.second - s.first) < EPS;
}

bool intersectSS(const line &s, const line &t){
	return ccw(s.first, s.second, t.first) * ccw(s.first, s.second, t.second) <= 0 &&
		ccw(t.first, t.second, s.first) * ccw(t.first, t.second, s.second) <= 0;
}


double distanceSP(const line &s, const xy_t p){
	xy_t r = projection(s, p);
	if(intersectSP(s, r)) return abs(r - p);
	return min(abs(s.first - p), abs(s.second - p));
}

double distanceSS(const line &s, const line &t){
	if(intersectSS(s, t)) return 0.0;
	return min(min(distanceSP(s, t.first), distanceSP(s, t.second)),
		min(distanceSP(t, s.first), distanceSP(t, s.second)));
}

xy_t crosspoint(const line &l, const line &m){
	double a = cross(l.second - l.first, m.second - m.first);
	double b = cross(l.second - l.first, l.second - m.first);
	if(abs(a) < EPS && abs(b) < EPS) return m.first;
	if(abs(a) < EPS) assert(false);
	return m.first + b / a * (m.second - m.first);
}

int main(){
	int dx[] = {1, 0, -1, 0};
	int dy[] = {0, 1, 0, -1};
	int memo[20][20][7];
	char field[20][20];
	int w, h;
	while(cin>> w >> h &&( w || h)){
		fill(&field[0][0], &field[19][19]+1, '0');
		memset(memo, -1, sizeof(memo));
		int sx, sy, gx, gy;
		for(int i = 1; i <= h; i++){
			for(int j= 1; j <= w; j++){
				cin>> field[i][j];
				if(field[i][j] == '2') {
					sx = j;
					sy = i;
				}
				if(field[i][j] == '3'){
					gx = j;
					gy = i;
				}
			}
		}
		memo[sx][sy][6] = 0;
		queue<PP> que;
		que.push(PP(6, P(sx, sy)));
		bool ok = false;
		while(!que.empty()){
			PP pp = que.front();
			que.pop();
			int p1 = pp.first;
			int p = p1;
			int x = pp.second.first;
			int y = pp.second.second;
			if(x == gx && y == gy){
				cout << memo[x][y][p] << endl;
				ok = true;
				break;
			}
			if(field[y][x] == '4') p = 6;
			if(p == 1) continue;
			for(int i = 0; i < 4; i++){
				int x2 = x + dx[i];
				int y2 = y + dy[i];
				int p2 = p - 1;
				if(field[y2][x2] != '0' && memo[x2][y2][p2] == -1){
					memo[x2][y2][p2] = memo[x][y][p1] + 1;
					que.push(PP(p2, P(x2, y2)));
				}
			}
		}
		if(!ok) cout << -1 << endl;
	}
	return 0;
}

Measured memory_bytes: 0