(use scheme.list)
(use util.match)

(define (ii)
  (string->number (read-line)))

(define (li)
  (let ((s (read-line)))
    (map string->number (string-split s " "))))

(let* ((N (ii))
       (A (li))
       (B (li)))
  (let ((ans (count (lambda (p)
                      (match-let1 (a b) p
                        (<= a b)))
                    (zip A B))))
    (print ans)))