#include <bits/stdc++.h>
using namespace std;
#define MAX 2550
int n,xf,yf;
char m[MAX][MAX];
bool v[MAX][MAX];
//PENDIENTE
struct solve{
	int x;
	int y;
	int d;
	int t;
	solve(int x1,int y1,int d1,int t1) : x(x1),y(y1),d(d1),t(t1){}
};
int bfs(){
	solve in(0,0,0,1);
	queue<solve>Cola;
	Cola.push(in);
	int dx[4]={0,0,1,-1};
	int dy[4]={1,-1,0,0};
	while(!Cola.empty()){
		solve now = Cola.front();
		Cola.pop();
		if(now.x==xf&&now.y==yf)return now.d;
		if(v[now.x][now.y])continue;
		v[now.x][now.y]=true;
		for(int i=0;i<4;i++){
			int x=now.x+dx[i];
			int y=now.y+dy[i];
			now.t++;
			if(x>=0&&x<=n&&y>=0&&y<=n){
				if(m[x][y]=='2'||m[x][y]=='3'||m[x][y]=='4'||m[x][y]=='5'||m[x][y]=='6'||m[x][y]=='7'||m[x][y]=='8'||m[x][y]=='9'){
					if(m[x][y]+48%now.t!=0){
						solve r(x,y,now.d+1,now.t);
					}
				}
				else solve r(x,y,now.d+1,now.t);
			}
		}
	}
	return -1;
}
	int main (){
		ios_base::sync_with_stdio(0);
		cin.tie(0);
		cin>>n;
		for(int i=0;i<n;i++){
			for(int j=0;j<n;j++){
				cin>>m[i][j];
			}
		}
		xf=n-1;
		yf=n-1;
		cout << bfs();
	}