(define (median str)
  (let* ((sorted (sort str)))
    (if (= (modulo (length str) 2) 1)
        (list-ref sorted (quotient (length str) 2))
        (/. (+ (list-ref sorted (quotient (length str) 2))
               (list-ref sorted (- (quotient (length str) 2) 1))) 2))))

(define (create-list n)
  (if (= n 0) '()
      (cons (read) (create-list (- n 1)))))

(define (main args)
  (print (median (create-list (read)))) 0)