(define (numbers count)
  (define (seq number result)
    (if (= 0 number)
        result
      (seq (- number 1) (cons number result))))
  (seq count '()))

(define (read-chapters chapters-left problem-counts)
  (if (= 0 chapters-left)
      (reverse problem-counts)
    (read-chapters (- chapters-left 1) (cons (read) problem-counts))))

(define (page-numbers problem-count starting-page per-page)
  (define (seq number result)
    (if (> number problem-count)
        result
      (seq (+ number 1) (cons (+ starting-page (quotient (- number 1) per-page)) result))))
  (reverse (seq 1 '())))

(let* ((chapters (read))
       (problems-per-page (read))
       (problem-counts (read-chapters chapters '()))
       (page 1))
  (writeln (foldl (lambda (problem-count result)
                    (let ((specials
                           (foldl (lambda (problem-number page-number result)
                                    (+ result (if (= problem-number page-number) 1 0)))
                                  0
                                  (numbers problem-count)
                                  (page-numbers problem-count page problems-per-page))))
                      (set! page (+ page (ceiling (/ problem-count problems-per-page))))
                      (+ result specials)))
                  0 problem-counts)))