import java.util.*;
import java.util.Arrays;

public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] a = new int[n];
		int[] b = new int[n];
		for(int i=0;i<n;i++){
			a[i] = sc.nextInt();
		}
		b[0] = 1;
		int now = 1;
		do{
			if(b[a[now-1]-1]==0){
				b[a[now-1]-1]=b[now-1]+1;
				now = a[now-1];
			}else{
				System.out.println(-1);
				break;
			}
			if(now==2){
				System.out.println(b[1]-1);
				break;
			}
		}while(true);
	}
}
/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