import           Control.Monad
import           Data.Maybe
import qualified Data.ByteString.Char8 as BS

readInt = fst . fromJust . BS.readInt
readIntList = map readInt . BS.words
getInt = readInt <$> BS.getLine
getIntList = readIntList <$> BS.getLine

main = do
  [a] <- getIntList
  putStr $ if a == 25 then "Christmas" else ""
  putStr $ if a == 24 then "Christmas Eve" else ""
  putStr $ if a == 23 then "Christmas Eve Eve" else ""
  putStr $ if a == 22 then "Christmas Eve Eve Eve" else ""