import Control.Applicative
import Text.Printf

f :: [Int] -> String
f xs@(x:y:_)
  | x == 1 = "NO"
  | y == 1 = "NO"
  | and $ map odd xs  = "NO" 
  | otherwise = "YES"

main = do
  xs <- take 2 <$> fmap (read :: String -> Int) . words <$> getLine
  putStrLn $ f xs