import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int[] a = new int[n+1];
    boolean[] b = new boolean[n+1];
    for(int i = 1; i < n+1; i++){
      a[i] =sc.nextInt();
    }
    int i = 1,count = 0;
    while(true){
      if(i == 2){
        System.out.println(count);
        break;
      }
      if(b[i]){
        System.out.println(-1);
        break;
      }
      b[i] = true;
      i = a[i];
      count++;
    }
  }
}

/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