import java.util.Scanner;

public class Main{

	public static void main(String[] args){
		new Main().solve();
	}
	
	void solve(){
		Scanner sc=new Scanner(System.in);
		int N=sc.nextInt();
		int[]a=new int[N+1];
		for(int i=0;i<N;i++){
			a[i+1]=sc.nextInt();
		}
		
		int count=0;
		int now=1;
		while(count<N && now!=2){
			now=a[now];
			count++;
		}
		
		if(now==2)System.out.println(count);
		else System.out.println(-1);
	}
	
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz