(defun mapper (x y)
  (let* ((map-y (1- x))
         (map-x (1- y))
         (mp (make-array (list (1+ map-y) (1+ map-x)) :initial-element #\. :element-type 'standard-char))
         (map-out-char #\.))
    (defun accessor (accessor-x accessor-y)
      (if (and (<= 0 accessor-x map-x) (<= 0 accessor-x map-x))
          (aref mp accessor-y accessor-x)
          map-out-char))
    (loop :for yy :from 0 :upto map-y
          :do(loop :for xx :from 0 :upto map-x
                   :do(setf (aref mp yy xx) (read-char))) :do(read-char))))


(let* ((n (read))
       (w (read)))
  (mapper n w)
  (if
   (loop :for k :from 0 :upto n
         :always (loop :for j :from 0 :upto w
                       :always (if (char= #\# (accessor k j))
                                   (or (char= #\# (accessor (1- k) j))
                                       (char= #\# (accessor (1+ k) j))
                                       (char= #\# (accessor k (1- j)))
                                       (char= #\# (accessor k (1+ j))))
                                   t)))
   (princ "Yes")
   (princ "No")))
