module Main where
 
main :: IO ()
main = readLn >>= putStrLn . solve
 
solve :: Int -> String
solve n | isnotPrime n = "YES"
        | otherwise    = "NO"
 
isnotPrime :: Int -> Bool
isnotPrime = (>=3) . length . primes
 
primes :: Int -> [Int]
primes n = go n 2
 
go :: Int -> Int -> [Int]
go x i | i * i > x = [x]
       | x `mod` i == 0 = i : go (x `div` i) i
       | otherwise = go x $ succ i