import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] an = new int[n+1];
        for (int i = 1; i <= n; i++) {
            an[i] = sc.nextInt();
        }

        int j = an[1];
        for (int i = 1; i <= n; i++) {
            if (j == 2) {
                System.out.println(i);
                System.exit(0);
            }
            j = an[j];
        }
        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