(define s '"")

(define (count lst len)


  (cond ((null? lst) 0)
        ((PAIR? lst) len)
        (else (+ 1 (
                    ;(cond (( EQUAL? '()  (cdr '(  4 )) ) "hello" ) )
                    count (cdr s (+ len 1) )
                          )))))

(define (count1 lst len)

  ;(display lst)
  ;(display (not (PAIR? lst)) )
  ;(display "\n")
 (cond ((null? lst) len  )
        ((not (PAIR? lst)) len )
        (else  (
                    count1 (cdr lst  ) (+ len 1)
                          ))))

 (define (cc c)
       c
  )

(define (reverse_ list_  result  position )

    (cond ((null? list_)  result  )
          ( (and (= position 1  ) (PAIR?  list_) (LIST? list_) )
                          ;;(display copy) (display li)
                          ;;(display (car li))
                          ;;(display (cdr li))
                            (cons  (car list_)  result ) )
             ( (and  (= position 1  ) (PAIR?  list_) (not (LIST? list_)) )
                          ;;(display copy) (display li)
                          ;;(display (car li))
                          ;;(display (cdr li))
                          ;; (display li)
                          (cons   list_   result ) )
             (else
                        (reverse_ (cdr list_) (cons (car list_) result  )  ( - position 1) )
                     )
     )
)

(define (check li copy possible_pair_position)
  ; (display (PAIR? (cdr li)))
   ; (display (LIST? (cdr li)))
    #|(display "\n")
    (display (PAIR? li))
    (display (LIST? li))
    (display (PAIR? (cdr li)))
    (display (cdr li) )
    (display  possible_pair_position)
    (display copy)
     (display "\n")|#
     #| (display "\n")
      (display (PAIR? (cdr li)))
       (display li)
         (display (cdr li))
        (display "\n")|#
      (cond ((null? li)  copy  )
            ( (and (=  possible_pair_position 1  ) (PAIR?  li) (LIST? li) )
                          ;;(display copy) (display li)
                          ;;(display (car li))
                          ;;(display (cdr li))
                         (reverse_ (cons  (car li)  copy ) '() 5)     )
             ( (and (=  possible_pair_position 1  ) (PAIR?  li) (not (LIST? li)) )
                          ;;(display copy) (display li)
                          ;;(display (car li))
                          ;;(display (cdr li))
                          ;; (display li)
                         (reverse_ (cons   li   copy ) '() 5)  )
           ( (=  possible_pair_position 1  )
                         (display (cdr li))  (cons  (car li) copy ) )
           (else

     #|                 (display "\n")
       (display (null? li))
      (display li)
      (display copy)
      (display "\n")
      (display (car li))|#
      (check (cdr li  ) (cons (car li) copy )   (- possible_pair_position 1) )

            )
       )

 )
(define (second my_list)
     (define len  ( count1 my_list 0) )
     (cond ((< len 2) "less than 2")
           ((= len 2) '() )
           (else  ( check (cddr my_list) '()  (- len 2) )

                           )
           )


  )
     (define r '() )

(define (first my_list)

     (cond ((< ( count1 my_list 0) 2) '("less than 2" "fff") )
           ((= ( count1 my_list 0) 2)
                                       (cond ((and (not (LIST? my_list)) (PAIR? x) )
                                      (set! r (cons ( cdr my_list) r))
                                        (set! r (cons (car my_list) r))
                                        ;(display (cdr my_list))

                                  r  )
                                       (else (
                                               (set! r (cons ( cadr my_list) r))
                                        (set! r (cons (car my_list) r))
                                        ;(display (cdr my_list))

                                  r
                                              ) )
                                             )                  )
           ((> ( count1 my_list 0) 2)
                                        (set! r (cons ( cadr my_list) r))
                                        (set! r (cons (car my_list) r))
                                        ;(display (cdr my_list))

                                  r )

                    (else  '(car my_list)

                           )
           )


  )


(define (parse_pair t)
  (cond ((null? t) 0)

        (else (+ 1
                 (parse_pair  (cdr t))
         ))))

(define (parse_not_right_list my_list)
  (cond ((LIST? my_list) "LIST")
        ((PAIR? my_list) (parse_pair my_list))

   )
)
;(count1 '( 4 5 5 5  5 . 6) 0)
;(first '(5   6 . 2 ) )
 (define x   '( (5 . 4)     ) )
 (display x)
(display "\n")
;(display x)
;(PAIR? '(2 . 22))
(first  x)
;(second x)
 ;(reverse_ (second x) '()  5 )
 ;(define x  '(3 5 5 6 5 6 2 4 (5 . 4)  7))
 ;(LIST? x)
;(check x '())
;(second '(5 (6 . 2) 5 53))
 #|(cond ((null? '() ) "HH"))
  (PAIR? '( 4 . 8) )
 (cond (ATOM? cdr '(  4 . 8 )) )
  (cond (( EQUAL? '()  (cdr '(  4 . 8 )) ) "hello" ) )|#
#|(  cdr '( 4 . (6 5 5 4)) )
(parse_not_right_list '(4 5

                          6 2  5  4))
(define x '( 4  5 6 2  5  5  6 4  6  3  ))
(first x)
(second x)|#
;(parse_pair x)
#|(count '(4 5 4 2 5 3 5))
(define sec (second '(2 3 5 4)))
(define fir (first '(2  3 5 4)))
(define re '() )
(set! re (cons sec '()))
(set! re (cons fir re))|#