using System;

public class Program

{

    public static void Main()

    {

        int[] a = {2,3,6,6,8,9,10,10,10,12,12};

        int[] b  = new int[a.Length]; 

        removeDuplicates(a);

    }

        public static void removeDuplicates(int[] input){

        int j = 0;

        int i = 1;

        //return if the array length is less than 2

        if(input.Length < 2){

            return;

        }

        while(i < input.Length){

            if(input[i] == input[j]){

                i++;

            }else{

                input[++j] = input[i++];

            }    

        }

      //  int[] output = new int[j+1];

        for(int k=0; k<j+1; k++){

            Console.WriteLine(input[k]);

        }

    }

}