(eval-when (:compile-toplevel :load-toplevel :execute)
  (defparameter OPT
    #+swank '(optimize (speed 3) (safety 2))
    #-swank '(optimize (speed 3) (safety 0) (debug 0)))
  #+swank (progn (ql:quickload '(:cl-debug-print :fiveam))
                 (shadow :run)
                 (use-package :fiveam)))
#+swank (cl-syntax:use-syntax cl-debug-print:debug-print-syntax)

;; BEGIN_INSERTED_CONTENTS
(declaim (ftype (function * (values fixnum &optional)) read-fixnum))
(defun read-fixnum (&optional (in *standard-input*))
  (macrolet ((%read-byte ()
               `(the (unsigned-byte 8)
                     #+swank (char-code (read-char in nil #\Nul))
                     #-swank (sb-impl::ansi-stream-read-byte in nil #.(char-code #\Nul) nil))))
    (let* ((minus nil)
           (result (loop (let ((byte (%read-byte)))
                           (cond ((<= 48 byte 57)
                                  (return (- byte 48)))
                                 ((zerop byte) ; #\Nul
                                  ;; (return-from read-fixnum 0)
                                  (error "Read EOF or #\Nul."))
                                 ((= byte #.(char-code #\-))
                                  (setf minus t)))))))
      (declare ((integer 0 #.most-positive-fixnum) result))
      (loop
        (let* ((byte (%read-byte)))
          (if (<= 48 byte 57)
              (setq result (+ (- byte 48) (the fixnum (* result 10))))
              (return (if minus (- result) result))))))))

(defmacro dbg (&rest forms)
  #+swank
  (if (= (length forms) 1)
      `(format *error-output* "~A => ~A~%" ',(car forms) ,(car forms))
      `(format *error-output* "~A => ~A~%" ',forms `(,,@forms)))
  #-swank (declare (ignore forms)))

(defmacro define-int-types (&rest bits)
  `(progn
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "UINT~A" b)) () '(unsigned-byte ,b))) bits)
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "INT~A" b)) () '(signed-byte ,b))) bits)))
(define-int-types 2 4 7 8 15 16 31 32 62 63 64)

(defmacro println (obj &optional (stream '*standard-output*))
  `(let ((*read-default-float-format* 'double-float))
     (prog1 (princ ,obj ,stream) (terpri ,stream))))

(defconstant +mod+ 1000000007)

;; Body

(defun main ()
  (let* ((n (read))
         (x (read))
         (as (make-array n :element-type 'uint32))
         (res 0))
    (dotimes (i n) (setf (aref as i) (read-fixnum)))
    (dotimes (i (- n 1))
      (let ((delta (- (+ (aref as i) (aref as (+ i 1))) x)))
        (when (> delta 0)
          (let* ((delta1 (min delta (aref as (+ i 1))))
                 (delta0 (- delta delta1)))
            (decf (aref as i) delta0)
            (decf (aref as (+ i 1)) delta1)
            (incf res delta)))))
    ;; (loop for i from 1 below (- n 1)
    ;;       do (let ((delta (- (+ (aref as i) (aref as (+ i 1))) x)))
    ;;            (when (> delta 0)
    ;;              (let ((delta-i (min (aref as i) delta)))
    ;;                (decf (aref as i) delta-i)
    ;;                (incf res delta-i))))
    ;;       finally (let ((delta (- (+ (aref as (- n 2)) (aref as (- n 1))) x)))
    ;;                 (when (> delta 0)
    ;;                   (decf (aref as (- n 1)) delta)
    ;;                   (incf res delta))))
    (println res)))

#-swank(main)


Measured memory_bytes: 13032