#!/usr/bin/env gosh
(define (separate-number n)
  (define (iter n acc)
    (if (< n 10)
        (cons n acc)
        (iter (div n 10) (cons (mod n 10) acc))))
  (iter n '()))

(define (append-number lst)
  (define (iter lst acc)
    (if (null? lst)
        acc
        (iter (cdr lst) (+ (* 10 acc) (car lst)))))
  (iter lst 0))

(let ((n (read)))
  (display (append-number (sort (separate-number n) >)))
  (newline))