import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n  = Integer.parseInt(sc.next());
		int[] a = new int[n + 1];
		for (int i = 1; i <= n; i++)
			a[i] = Integer.parseInt(sc.next());
		int tem = a[1];
		int ans = 1;
		while (tem != 2) {
			tem = a[tem];
			ans++;
			if (ans > n) {
				ans = -1;
				break;
			}
		}
		System.out.println(ans);
	}
}
/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