import java.util.Scanner;
public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] a = new int[N+1];
        for(int i = 1;i <= N;i++){
            a[i] = sc.nextInt();
        }
        int count = 1;
        int x = a[1];
        for(int i = 1;i <= N;i++){
            if(x == 2){
                System.out.println(count);
                return;
            }
            count++;
            x = a[x];
        }
        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