import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		ArrayList<String> arr = new ArrayList();
		Scanner input = new Scanner(System.in);
		String str,str2;
		String empty = "";
		str = input.nextLine();
		for(int i = 0;i<str.length();i++)
		{
			str2 = empty;
			str2 += str.charAt(i);
			arr.add(str2);
		}
		for(int i = 0;i < arr.size(); i++)
		{
			if(i != arr.size()-1)
			{
				if(arr.get(i).equals(arr.get(i+1)))
				{
					arr.remove(i);
					arr.remove(i);
					i--;
				}
			}
		}
		for(int i = 0;i < arr.size();i++)
		{
			System.out.print(arr.get(i));
		}
	}
}