import java.util.Scanner;

public class Main{
  static int n;
  static int[] a;

  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);

    n = sc.nextInt();
    a = new int[n];
    for(int i = 0; i < n; i++){
      a[i] = sc.nextInt();
    }

    int p = 1, count = 0;
    while(p != 2 && count <= n){
      p = a[p - 1];
      ++count;
    }

    if(p == 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