ReqemlerdenMinimumEded

import java.util.Scanner;

public class Main {


    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int num = scan.nextInt();
        int numCopy = num;
        int count = 0;
        int newNum = 0;
        for (; numCopy > 0; count++){
            numCopy/=10;
        }

        int arr[] = new int[count];
        for (int i = 0; i<arr.length; i++){
            arr[i] = num%10;
            num/=10;
        }


        for (int j = 0; j < arr.length; j++) {
            int min = arr[0];

            for (int i = 1; i < arr.length; i++) {
                min = (arr[i] < min) ? arr[i] : min;
            }

            newNum = newNum * 10 + min;

            for (int i = 0; i < arr.length; i++) {
                if (arr[i] == min){
                    arr[i] = 10;
                    break;
                }
            }
        }
        System.out.println(newNum);

    }

}