题解 | #图片整理#

import java.util.Scanner;
import java.util.*;
import java.util.stream.Stream;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        Stream.of(in.nextLine().split("")).sorted().reduce((x, y) -> x + y).ifPresent(System.out::println);
    }
}