import java.util.*; public class Exercise62{ public static void main (String[] args){ Scanner sc = new Scanner(System.in); String str = sc.next(); String[] array = str.split(""); Arrays.sort(array, Comparator.reverseOrder()); str = ""; for (int i = 0; i < array.length; i++){ str += array[i]; } System.out.println(str); } }