
import java.util.Scanner;

class Main {

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

        int n = sc.nextInt();
        int[] a = new int[n];
        
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
        }
        int sum = 0;
        int i = 0;
        do {
            i = a[i];
            i = i - 1;
            sum++; 
            if (sum == n) {
                sum = -1;
                break;
            }
        } while (i != 1);
        System.out.println(sum);      
    }
}

/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