using System;

public class Program

{

    public static void Main()

    {

        int[] arr1 = new int[]{1, 5, 6, 1, 4, 6, 2, 1};

        int[] arr2 = new int[arr1.Length];

        int count =0;

        for(int i=0;i<arr1.Length;i++)

        {

            if(Array.IndexOf(arr2, arr1[i]) == -1)

            {

                arr2[count++]=arr1[i];

            }

        }

        for(int i=0;i<count;i++)

            Console.WriteLine(arr2[i]);

    }

}