(use srfi.13)  ; string
(use srfi.42)  ; list-ec
(use srfi.197) ; chain
(use data.queue)
(use gauche.collection)
(use gauche.dictionary)
(use gauche.generator)
(use gauche.sequence)
(use scheme.list)
(use scheme.vector)
(use util.match)

(define input read-line)

(define (ii)
  (string->number (input)))

(define (li)
  (let ((s (input)))
    (map string->number (string-split s " "))))

(define-method prn* ((seq <sequence>))
  (for-each-with-index (^(i x)
                         (when (> i 0)
                           (display " "))
                         (display x))
                       seq)
  (newline))

(define (prn . args)
  (prn* args))

(define (prn-yn b)
  (prn (if b "Yes" "No")))

(define-syntax ->/prn
  (syntax-rules ()
    ((_ x fns ...)
     (-> x fns ... prn))))

(define-syntax prn/d
  (syntax-rules ()
    ((_ expr ...)
     (with-output-to-port (current-error-port)
       (^()
         (prn expr ...))))))

(define-syntax let/g
  (syntax-rules ()
    ((_ var body ...)
     (generate (lambda (var) body ...)))))

(define ord char->integer)
(define chr integer->char)

(define int string->number)
(define str x->string)
(define string* (apply$ string))

(define-method min ((xs <sequence>))
  (fold min (~ xs 0) xs))
(define-method max ((xs <sequence>))
  (fold max (~ xs 0) xs))

(define (minmax . xs)
  (values->list (apply min&max xs)))
(define-method minmax ((xs <sequence>))
  (values->list (apply min&max xs)))

(define (sum xs)
  (fold + 0 xs))

(define (divmod a b)
  (values->list (div-and-mod a b)))

(define (ceildiv a b)
  (div (+ a (1- b)) b))

(define (1+ n) (+ n 1))
(define (1- n) (- n 1))
(define (!= a b) (not (= a b)))
(define (midpoint a b) (div (+ a b) 2))

(define pow
  (case-lambda
   ((a b) (expt a b))
   ((a b m) (expt-mod a b m))))

(define gcd* (apply$ gcd))
(define sq square)
(define isqrt exact-integer-sqrt)

(define pos? positive?)
(define neg? negative?)

(define (cmp< a b) (< (compare a b) 0))
(define (cmp> a b) (> (compare a b) 0))

(define ++ string-append)

(define zip (map$ list))
(define all every)
(define any-ec any?-ec)
(define all-ec every?-ec)
(define concat concatenate)
(define foldl fold-left)

(define (pairwise xs)
  (zip xs (cdr xs)))

(define (comb n k)
  (if (or (< k 0) (> k n))
      0
      (let loop ((i 0)
                 (x 1))
        (if (= i k)
            x
            (loop (1+ i) (div (* x (- n i)) (1+ i)))))))

(define-method frequencies ((xs <sequence>))
  (let1 ht (make-hash-table equal-comparator)
    (for-each (^x (hash-table-update! ht x 1+ 0)) xs)
    (new ht)))

;; '(a b c) -> op(op(op(init, a), b), c)
(define (scanl op init xs)
  (define (f a b)
    (let1 t (op b a)
      (values t t)))

  (map-accum f init xs))

;;'(a b c) ->  op(a, op(b, op(c, init)))
(define (scanr op init xs)
  (define (f a b)
    (let1 t (op a b)
      (values t t)))

  (reverse (map-accum f init (reverse xs))))

(define-macro (input! vars . body)
  (let ((binds (map (^x
                     (cond
                      ((symbol? x)
                       `((,x) (values (ii))))
                      ((list? x)
                       (if (= 1 (length x))
                           `(,x (values (li)))
                           `(,x (apply values (li)))))
                      (else
                       (error "symbol or list required, but got:" x))))
                    vars)))
    `(let*-values ,binds
       ,@body)))

(define-macro (! self quoted-name . args)
  (let ((name (cadr quoted-name)))
    `(,name ,self ,@args)))

(define-macro (d/ . args)
  (let ((ss (map (^(expr)
                   `(list ,(x->string expr) ,expr))
                 args)))
    `(prn/d (list ,@ss))))

(define mlet match-let)
(define mlet* match-let*)
(define mlet1 match-let1)

(define-macro (mfn pat . body)
  (let ((args (gensym)))
    `(lambda ,args
       (mlet1 ,pat ,args
         ,@body))))

(define-macro (mfn1 pat . body)
  (let ((arg (gensym)))
    `(lambda (,arg)
       (mlet1 ,pat ,arg
         ,@body))))

(define-method len ((coll <collection>))
  (size-of coll))

(define (digits n)
  (map digit->integer (str n)))

(define (digits->int ds)
  (fold-left (^(a b) (+ (* 10 a) b)) 0 ds))

(define (-> x . fns)
  (call-with-values (^() (values x))
    (apply compose (reverse fns))))

(define (rep n thunk)
  (list-ec (: _ n)
           (thunk)))

(define (memoize fn)
  (let ((cache (make-hash-table 'equal?)))
    (lambda args
      (if (hash-table-exists? cache args)
          (hash-table-get cache args)
          (let ((val (apply fn args)))
            (hash-table-put! cache args val)
            val)))))

(define (zip-longest . args)
  (let* ((n (apply max (map length args)))
         (xxs (map (^(xs)
                     (append xs (make-list (- n (length xs)) #f)))
                   args)))
    (map (pa$ delete #f)
         (apply zip xxs))))

(define (accumulate xs)
  (list->vector (scan-left + 0 xs)))

(define (accum xs)
  (let ((vs (accumulate xs)))
    (case-lambda
     ((l r)  ; [l, r]
      (- (~ vs r) (if (> l 0) (~ vs (1- l)) 0)))
     ((r)    ; [0, r]
      (~ vs r)))))

(define (string->set s)
  (list->set eqv-comparator (string->list s)))

(define (difference xs ys)
  (let ((excludes (list->set ys)))
    (filter (^x (not (set-contains? excludes x))) xs)))

(define (uniq xs)
  (let1 ht (make-hash-table 'equal?)
    (for-each (^x (hash-table-put! ht x #t))
              xs)
    (hash-table-keys ht)))

;; <hash-table>

(define (make-dict)
  (new (make-hash-table equal-comparator)))

(define-method new ((self <hash-table>))
  (match-lambda*
   (('get key)
    (hash-table-get self key 0))
   (('get key default)
    (hash-table-get self key default))
   (('put! key value)
    (hash-table-put! self key value))
   (('update! key proc)
    (hash-table-update! self key proc 0))
   (('update! key proc default)
    (hash-table-update! self key proc default))
   (('push! key value)
    (hash-table-push! self key value))
   (('keys)
    (hash-table-keys self))
   (('values)
    (hash-table-values self))
   (('contains? key)
    (hash-table-contains? self key))
   (('items)
    (hash-table->alist self))
   (('map fn)
    (hash-table-map self fn))))

(define (alist->dict alist)
  (new (alist->hash-table alist equal-comparator)))


(input! (N)
  (->
   (~ (str N) 0)
   (^c (or (eqv? c #\4)
           (eqv? c #\5)))
   prn-yn))