import java.util.*;
 
public class Main{
    public static void main(String args[] ) throws Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] array = new int[n];
        int on = 0;
        for (int i = 0; i < n; i++) {
            array[i] = sc.nextInt();
        }
        int m = 0;
        int count = 0;
        for (int i = 0; i < n; i++) {
            m = array[m] - 1;
            count++;
            if (m == 1) {
                break;
            }
        }
        if (count == n) {
            System.out.println(-1);
        } else {
            System.out.println(count);
        }
    }
}

/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