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

public class Solution {


	public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
		String s = in.next();
		String result = "";
		if(s.length()==1)
			System.out.println(s);
		else {
			for(int i=0; i<s.length(); i++){
				if((i<s.length()-1)&&(s.charAt(i)==s.charAt(i+1)))
					i++;
				else if(result.charAt(result.length()-1)==s.charAt(i)){
					if(result.length()==1)
                        result = "";
                    else
                        result = result.substring(0, result.length());
                }
				else
					result+=s.charAt(i);
			}
		}
		if(result.equals(""))
			System.out.println("Empty String");
		else
			System.out.println(result);
    }


}