(in-package :cl-user)
(eval-when (:compile-toplevel :load-toplevel :execute)
  (sb-int:defconstant-eqx opt
    #+swank '(optimize (speed 3) (safety 2))
    #-swank '(optimize (speed 3) (safety 0) (debug 0))
    #'equal)
  #+swank (ql:quickload '(:cl-debug-print :fiveam) :silent t)
  #-swank (set-dispatch-macro-character
           #\# #\> (lambda (s c p) (declare (ignore c p)) `(values ,(read s nil nil t)))))
#+swank (cl-syntax:use-syntax cl-debug-print:debug-print-syntax)

(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)

(defconstant +mod+ 1000000007)

(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)))

(declaim (inline println))
(defun println (obj &optional (stream *standard-output*))
  (let ((*read-default-float-format* 'double-float))
    (prog1 (princ obj stream) (terpri stream))))

;; BEGIN_INSERTED_CONTENTS
(defpackage :cp/read-fixnum
  (:use :cl)
  (:export #:read-fixnum))
(in-package :cp/read-fixnum)

(declaim (ftype (function * (values fixnum &optional)) read-fixnum))
(defun read-fixnum (&optional (in *standard-input*))
  "NOTE: cannot read -2^62"
  (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
                                  (error "Read EOF or #\Nul."))
                                 ((= byte #.(char-code #\-))
                                  (setq minus t)))))))
      (declare ((integer 0 #.most-positive-fixnum) result))
      (loop
        (let* ((byte (%read-byte)))
          (if (<= 48 byte 57)
              (setq result (+ (- byte 48)
                              (* 10 (the (integer 0 #.(floor most-positive-fixnum 10))
                                         result))))
              (return (if minus (- result) result))))))))

(defpackage :cp/run-length
  (:use :cl)
  (:export #:map-run-length))
(in-package :cp/run-length)

(declaim (inline map-run-length))
(defun map-run-length (function seq &key (test #'eql))
  "Applies FUNCTION to each equal successive element of SEQ. FUNCTION must take
two arguments: the first one receives an element in SEQ and the second one
receives the number of the successive elements equal to the first.

Example: (map-run-length (lambda (x c) (format t \"~D ~D~%\" x c)) #(1 1 1 2 2 1 3))
1 3
2 2
1 1
3 1
"
     (declare (sequence seq)
              (function test function))
     (etypecase seq
       (vector
        (unless (zerop (length seq))
          (let ((prev (aref seq 0))
                (start 0))
            (loop for pos from 1 below (length seq)
                  unless (funcall test prev (aref seq pos))
                  do (funcall function prev (- pos start))
                     (setf prev (aref seq pos)
                           start pos)
                  finally (funcall function prev (- pos start))))))
       (list
        (when (cdr seq)
          (labels ((recur (lst prev count)
                     (declare ((integer 0 #.most-positive-fixnum) count))
                     (cond ((null lst)
                            (funcall function prev count))
                           ((funcall test prev (car lst))
                            (recur (cdr lst) prev (+ 1 count)))
                           (t (funcall function prev count)
                              (recur (cdr lst) (car lst) 1)))))
            (recur (cdr seq) (car seq) 1))))))

;; BEGIN_USE_PACKAGE
(eval-when (:compile-toplevel :load-toplevel :execute)
  (use-package :cp/run-length :cl-user))
(eval-when (:compile-toplevel :load-toplevel :execute)
  (use-package :cp/read-fixnum :cl-user))
(in-package :cl-user)

;;;
;;; Body
;;;

(defun main ()
  (let* ((n (read))
         (as (make-array n :element-type 'bit :initial-element 0))
         (bs (make-array n :element-type 'bit :initial-element 0)))
    (dotimes (i n)
      (setf (aref as i) (read-fixnum)))
    (dotimes (i n)
      (setf (aref bs i) (read-fixnum)))
    (let ((abs (bit-xor as bs))
          (res 0))
      (map-run-length (lambda (bit count)
                        (when (= bit 1)
                          (incf res)))
                      abs)
      (println res))))

#-swank (main)

;;;
;;; Test and benchmark
;;;

#+swank
(defun get-clipbrd ()
  (with-output-to-string (out)
    #+os-windows (run-program "powershell.exe" '("-Command" "Get-Clipboard") :output out :search t)
    #+os-unix (run-program "xsel" '("-b" "-o") :output out :search t)))

#+swank (defparameter *this-pathname* (uiop:current-lisp-file-pathname))
#+swank (defparameter *dat-pathname* (uiop:merge-pathnames* "test.dat" *this-pathname*))

#+swank
(defun run (&optional thing (out *standard-output*))
  "THING := null | string | symbol | pathname

null: run #'MAIN using the text on clipboard as input.
string: run #'MAIN using the string as input.
symbol: alias of FIVEAM:RUN!.
pathname: run #'MAIN using the text file as input."
  (let* ((*standard-output* (or out (make-string-output-stream)))
         (res (etypecase thing
                (null
                 (with-input-from-string (*standard-input* (delete #\Return (get-clipbrd)))
                   (main)))
                (string
                 (with-input-from-string (*standard-input* (delete #\Return thing))
                   (main)))
                (symbol (5am:run! thing))
                (pathname
                 (with-open-file (*standard-input* thing)
                   (main))))))
    (if out res (get-output-stream-string *standard-output*))))

#+swank
(defun gen-dat ()
  (uiop:with-output-file (out *dat-pathname* :if-exists :supersede)
    (format out "")))

#+swank
(defun bench (&optional (out (make-broadcast-stream)))
  (time (run *dat-pathname* out)))

;; To run: (5am:run! :sample)
#+swank
(it.bese.fiveam:test :sample
  (it.bese.fiveam:is
   (equal "1
"
          (run "4
0 0 0 1
1 1 0 1
" nil)))
  (it.bese.fiveam:is
   (equal "3
"
          (run "7
0 0 1 1 0 0 0
1 1 0 1 1 0 1
" nil)))
  (it.bese.fiveam:is
   (equal "5
"
          (run "20
0 1 1 0 1 1 1 0 0 0 0 1 1 0 0 0 0 0 0 0
1 0 1 1 1 0 0 0 0 0 0 1 1 1 0 1 1 1 1 1
" nil))))