(let* ((n (read)))

  (let1 num (let loop ((i 2)
		       (m n))
	      (cond ((< n (* i i)) 0)
		    ((= (mod m i) 0)
		     (+ 1 (loop i (div m i))))
		    (else
		     (loop (+ i 1) m))))
	(print (if (> num 2)
		   "YES"
		   "NO"))))