;; -*- coding: utf-8 -*-
(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 (set-dispatch-macro-character #\# #\> (lambda (s c p) (declare (ignore c p)) (read s nil (values) t))))
#+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*))
  (declare #.OPT)
  (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 #\-))
                                  (setf 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))))))))

(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)

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

(defconstant +mod+ 1000000007)

;; Body
;;;
;;; This is an implementation of binary indexed tree, specialized for the
;;; ordinary `+' operation. You had better to use the generalized-bit instead. I
;;; leave it just for my reference.
;;;

(declaim (inline bitree-inc!))
(defun bitree-inc! (bitree index1 index2 delta)
  "Destructively increments the vector: vector[INDEX] += DELTA"
  (declare ((simple-array uint31 (* *)) bitree)
           (uint31 index1 index2 delta))
  (destructuring-bind (len1 len2) (array-dimensions bitree)
    (declare (uint31 len1 len2))
    (do ((i index1 (logior i (+ i 1))))
        ((>= i len1) bitree)
      (declare ((integer 0 #.most-positive-fixnum) i))
      (do ((j index2 (logior j (+ j 1))))
          ((>= j len2))
        (setf (aref bitree i j)
              (rem (+ (aref bitree i j) delta) +mod+))))))

(declaim (inline bitree-sum))
(defun bitree-sum (bitree end1 end2)
  "Returns the sum: vector[0] + ... + vector[END-1]."
  (declare ((integer 0 #.most-positive-fixnum) end1 end2))
  (let ((res 0))
    (declare (uint31 res))
    (do ((i (- end1 1) (- (logand i (+ i 1)) 1)))
        ((< i 0) res)
      (declare ((integer -1 #.most-positive-fixnum) i))
      (do ((j (- end2 1) (- (logand j (+ j 1)) 1)))
          ((< j 0))
        (setf res (rem (+ res (aref bitree i j)) +mod+))))))

(defun main ()
  (declare #.OPT)
  (let* ((n (read))
         (m (read))
         (ss (make-array n :element-type 'uint31))
         (ts (make-array m :element-type 'uint31))
         (bitree (make-array (list n m) :element-type 'uint31 :initial-element 0)))
    (declare (uint16 n m))
    (dotimes (i n) (setf (aref ss i) (read-fixnum)))
    (dotimes (i m) (setf (aref ts i) (read-fixnum)))
    (dotimes (i n)
      (dotimes (j m)
        (when (= (aref ss i) (aref ts j))
          (bitree-inc! bitree i j (+ 1 (bitree-sum bitree i j))))))
    (println (mod (+ 1 (bitree-sum bitree n m)) +mod+))))

#-swank(main)


Measured memory_bytes: 76388