toInt :: (String -> Int)
toInt x = read x ::Int

getInts = do
  x <- getLine
  let y = (map$toInt)$words x
  return y

main :: IO ()
main = do
  a_c <- getInts
  print (if (filter (== (a_c !! 1)) [(a_c !! 0)..(a_c !! 2)]) == [] then "Yes"
        else "No")
