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import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;

public class TestString {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            String str = sc.nextLine();
            int length = str.length();
            List<String> list = new ArrayList<>();
            for (int i = 0; i < length; i++) {
                char c = str.charAt(i);
                if ((c <= 'Z' && c >= 'A') || (c <= 'z' && c >= 'a')) {
                    list.add(String.valueOf(c));
                }
            } 
			// 由于JDK 的比较器 String.CASE_INSENSITIVE_ORDER 不能比较相同字母的大小，比如A和a，
			// 如果不要求A和a排序的话可以直接用 Collections.sort(list，String.CASE_INSENSITIVE_ORDER);
            Collections.sort(list, new Comparator<String>() {
                @Override
                public int compare(String o1, String o2) {
                    int comp = String.CASE_INSENSITIVE_ORDER.compare(o1, o2);
                    if (comp == 0) {
                        comp = o1.compareTo(o2);
                    }
                    return comp;
                }
            });

            StringBuilder sb = new StringBuilder();
            int count = 0;
            for (int i = 0; i < length; i++) {
                char c = str.charAt(i);
                if ((c <= 'Z' && c >= 'A') || (c <= 'z' && c >= 'a')) {
                    sb.append(list.get(i));
                } else {
                    sb.append(String.valueOf(c));
                    count++;
                }
            }

            System.out.println(sb.toString());
        }
    }
}