
import java.util.Scanner;

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

		int[] button = new int[n];
		for (int i = 0; i < button.length; i++) {
			button[i] = sc.nextInt();
		}
		
		int next = 0;
		int cnt = 0;
		for (int i = 1;; i = next) {
			next = button[i - 1];
			cnt++;
			if (next == 2) {
				break;
			}
			
			if (cnt > n) {
				cnt = -1;
				break;
			}
			
		}
		System.out.println(cnt);

	}
}
/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