import Data.Bool
import Data.List

primes :: [Int]
primes = 2:3:[x | i<-[1..], j<-[-1,1], let x = 6*i+j, isPrime x]
 where isPrime n = null [i | i<-takeWhile (\x -> x^2 <= n) primes, mod n i == 0]

factorization :: Integer -> [Integer]
factorization n = unfoldr fact (n, primes)
 where
  q = (floor . sqrt . fromIntegral) n
  fact (n', pps@(p:ps))
   | n' == 1 = Nothing
   | p > q = Just (n',(1,pps))
   | otherwise = let (d,m) = divMod n' p' in if m==0 then Just (p',(d,pps)) else fact (n',ps)
   where p' = fromIntegral p

main = readLn >>= putStrLn . bool "NO" "YES" . (>2) . length . factorization