题解 | #图片整理#

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String s = scanner.nextLine();
        int[] arr = new int[128];
        for (int i = 0; i < s.length(); i++) {
            arr[s.charAt(i)]++;
        }
        for (int i = 0; i < 128; i++) {
            while (arr[i] > 0) {
                System.out.print((char) i);
                arr[i]--;
            }
        }
    }
}