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];
    for (int i = 1; i <= N; i++) {
      a[i] = sc.nextInt();
    }
    int light = 1;
    int[] used = new int[N + 1];
    int count = 0;
    while (true) {
      if (used[light] > 0) {
        System.out.println(-1);
        return;
      }
      if (light == 2) {
        System.out.println(count);
        return;
      }
      used[light] = 1;
      light = a[light];
      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