(defun main (&rest argv)
  (declare (ignorable argv))
  (let* ((n (read))
         (a (make-array n :element-type 'string))
         (h (make-hash-table))
         (check t))
    (dotimes (i n)
      (setf (aref a i) (read)))
    (dotimes (i n)
      (incf (gethash (aref a i) h 0)))
    (maphash (lambda (key val)
               (declare (ignore key))
               (when (> val (floor (1+ n) 2))
                     (setf check nil)))
             h)
    (format t "~a~%" (if check "YES" "NO"))))

(main)