import java.util.Scanner;

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

        int n = sc.nextInt();
        int[] buttons = new int[n];
        for(int i = 0; i < buttons.length;i++)
            buttons[i] = sc.nextInt() - 1;

        int now = 0;
        int tmp;
        for(int i = 0;i < n;i++)
        {
            tmp = buttons[now];
            if(tmp == 1) {
                System.out.println(i+1);
                System.exit(0);
            }
            else
                now = tmp;
        }
        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