import java.util.Scanner;
import java.util.Stack;

class Main {

    public static void main(String[] args) {
        new Main().compute();
    }

    void compute() {
        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() - 1;
        }
        int sum = 0;
        boolean[] passed = new boolean[N];
        for (int i = 0; !passed[i]; i = a[i], sum++) {
            passed[i] = true;
            if (i == 1) {
                System.out.println(sum);
                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