using System;

public class Program

{

    public static void Main()

    {

        int[] withDuplicates = new int[] {2,3,1,2,3,5,7,8,7};

        // output = 2 3 7

        int[] withoutDuplicates = new int[] {1,2,3,4,5,6,7,8};

        // output = -1

​

    }

}