import java.util.HashMap;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		HashMap<Integer, Integer> map = new HashMap<>();
		for (int i = 1; i <= N; i++) {
			map.put(i, sc.nextInt());
		}
		int cnt = 0;
		boolean can = false;
		for (int i = 1; cnt < N;) {
			cnt++;
			i = map.get(i);
			if (i ==  2) {
				can = true;
				break;
			}
		}
		if (can) {
			System.out.println(cnt);
		} else {
			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