import java.util.Scanner;

public class RemoveDuplicateLetters {

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