import java.util.Scanner;

// Java8
public class Main
{
	static Scanner sc = new Scanner(System.in);
	
	public static void main(String[] args) throws Exception
	{
		new Main().run();
	}
	
	void run()
	{
		int n = sc.nextInt();
		int[] as = new int[n+1];
		for(int i=1; i<=n; i++) as[i] = sc.nextInt();
		int p = 1;
		for(int i=1; i<=n; i++)
		{
			p = as[p];
			if(p==2)
			{
				System.out.println(i);
				return;
			}
		}
		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