hhhhhh

#include<queue>
using namespace std;
const int N = 1010;
struct node{
	int x;
	int y;
    int step;
};
int n, m, xx, yy;
node mp[N][N];
queue<node> q;
queue<int> g;
char ma[N][N];
bool flag, vip[N][N];
int main(){
	cin >> n >> m;
	for (int i = 1;i <= n;i ++){
		for (int j = 1;j <= m;j ++){
			cin >> ma[i][j];
			mp[i][j].x = i;
			mp[i][j].y = j;
            if (ma[i][j] == '2'){
                mp[i][j].step = 0;
                q.push(mp[i][j]);
            }
		}
	}
    vip[xx][yy] = 1;
    g.push(mp[xx][yy].step);
	while(q.size()){
		node k = q.front();
		q.pop();
		if (k.x - 1 > 0 && k.x <= n && !vip[k.x - 1][k.y] && ma[k.x - 1][k.y] == '1'){
			node v = k;
			v.x -= 1;
            v.step += 1;
            g.push(v.step);
            g.pop();
			vip[v.x][v.y] = 1;
			ma[v.x][v.y] = '2';
			q.push(v);
		}
		if (k.x + 1 <= n && k.x > 0 && !vip[k.x + 1][k.y] && ma[k.x + 1][k.y] == '1'){
			node v = k;
			v.x += 1;
            v.step += 1;
            g.push(v.step);
            g.pop();
			vip[v.x][v.y] = 1;
			ma[v.x][v.y] = '2';
			q.push(v);
		}
		if (k.y - 1 > 0 && k.y <= m && !vip[k.x][k.y - 1] && ma[k.x][k.y - 1] == '1'){
			node v = k;
			v.y -= 1;
            v.step += 1;
            g.push(v.step);
            g.pop();
			vip[v.x][v.y] = 1;
			ma[v.x][v.y] = '2';
			q.push(v);
		}
		if (k.y > 0 && k.y + 1 <= m && !vip[k.x][k.y + 1] && ma[k.x][k.y + 1] == '1'){
			node v = k;
			v.y += 1;
            v.step += 1;
            g.push(v.step);
            g.pop();
			vip[v.x][v.y] = 1;
			ma[v.x][v.y] = '2';
			q.push(v);
		}
	}
    for (int i = 1;i <= n;i ++){
		for (int j = 1;j <= m;j ++){
			if (ma[i][j] == '1'){
                flag = 1;
            }
		}
	}
    if (!flag) cout << g.front();
    else cout << -1;
	
	return 0;
}