import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int[] array = new int[N];
		int next =1;

		for(int i=0;i<N;i++) {
			array[i]=sc.nextInt();
		}
		for(int i=0;i<N;i++) {
			if(array[next-1] == 2) {
				System.out.println(i+1);
				System.exit(0);
			}
			next = array[next-1];
		}
		System.out.println(-1);
	}
	public static int sample() {
		return 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