import java.util.*;
class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    int n=sc.nextInt();
    int[] nums=new int[n];
    for(int i=0;i<n;i++){
      nums[i]=sc.nextInt();
    }
    boolean[] turned=new boolean[n];
    turned[0]=true;
    int now=1;
    int turns=0;
    while(true){
      turns++;
      now=nums[now-1];
      if(turned[now-1]){
        System.out.println(-1);
        return;
      }else if(now==2){
        System.out.println(turns);
        return;
      }
      turned[now-1]=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