import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int[] a = new int[N+1];
		for(int i = 1; i < N+1; i++){
			a[i] = sc.nextInt();
		}
		sc.close();

		int prev = 0;
		int cur = 1;
		int count = 0;

		while(cur != 2 && cur != 0){
			prev = cur;
			cur = a[cur];
			a[prev] = 0;
			count++;
		}
		if(cur == 2){
			System.out.println(count);
		}
		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