import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String s = scanner.nextLine();
        HashMap<Character, Integer> map = new HashMap<>();
        for (int i = 0; i < s.length(); i++) {
            map.merge(s.charAt(i), 1, Integer::sum);
        }
        int a = map.values().stream().sorted().findFirst().get();
        for (int i = 0; i < s.length(); i++) {
            if (map.get(s.charAt(i)) != a) {
                System.out.print(s.charAt(i));
            }
        }
    }
}