import java.util.Scanner;
import java.util.Stack;




public class CliperMessage_1654_Stack {
    public static void main(String[] arg1) {
        Scanner sc=new Scanner(System.in);
        StringBuilder sb=new StringBuilder();
        Stack<Character> stc=new Stack<>();
        sb.append(sc.nextLine());
        if(sb.length()<=200000){
            for(int i=0;i<sb.length();i++){
                if(stc.isEmpty()||(stc.peek()!=sb.charAt(i)))
                    stc.push(sb.charAt(i));
                else
                    if((stc.peek()==sb.charAt(i))) stc.pop();

            }

            StringBuilder sbn=new StringBuilder();
            int j=0;
            while(!stc.empty()) sbn.insert(j++, ""+stc.pop());
            System.out.println(sbn.reverse());
        }
    }
}