42.rkt

#lang racket

(define (chars n)
  (string->list (~a n #:min-width 6 #:pad-string "0")))

(define (char->str c)
  (match c
    [#\0 "((((((("]
    [#\1 "(((((("]
    [#\2 "((((("]
    [#\3 "(((("]
    [#\4 "((("]
    [#\5 "(("]
    [#\6 "("]
    [#\8 ")"]
    [#\9 "))"]
    [_ "horses"]))

(define (read-string s)
  (define in (open-input-string s))
  (define (loop)
    (unless (eof-object? (read in))
      (loop)))
  (loop))

(for/sum ([n (in-range 0 1000000)]) 
  (with-handlers ([(λ (_) #t) (λ (_) 0)])
    (read-string (list->string (sort (apply append (map string->list (map char->str (chars n))))
                                     (λ (a b) (< (char->integer a) (char->integer b))))))
    1))