import java.util.Scanner;
import java.util.Vector;

class Main{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		Vector<Integer> v=new Vector<Integer>();

		for(int i=0; i<n; i++) {
			int z=sc.nextInt();
			z--;
			v.add(z);
		}
		int now=0; int c=0;
		for(;;) {
			if(now==1) {
				System.out.println(c);
				break;
			}
			if(c>=n) {
				System.out.println(-1);
				break;
			}
			c++;
			now=v.get(now);
		}
	}
}
/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