import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            int temp = Integer.parseInt(sc.next());
            a[i] = temp - 1;
        }
        int idx = 0;
        int cnt = 0;
        for (int i = 0; i < n; i++) {
            cnt++;
            idx = a[idx];
            if (idx == 1) {
                System.out.println(cnt);
                return;
            } else if (idx == 0) {
                System.out.println(-1);
                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