import java.util.*;
public class Main{
public static void main(String args[]){
Scanner sc=new Scanner(System.in);
  int n=sc.nextInt();
  int []po=new int[n];
  boolean b=false;
  for(int i=0;i<n;i++){
  	po[i]=sc.nextInt();
  }
    int num=0;
    int i=0;
    for(;i<n;i++){
    	num=po[num]-1;
      if(num==1){b=true;break;}
    }
    System.out.println(b?i+1:-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