import java.util.Scanner;

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

    int N = scanner.nextInt();
    int[] a = new int[N];
    for (int i = 0; i < N; i++) a[i] = scanner.nextInt() - 1;
    int next = 0;
    for (int cnt = 1; cnt <= N; cnt++) {
      next = a[next];
      if (next == 1) {
        System.out.println(cnt);
        return;
      }
    }
    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