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));
}
}
}
}