import scala.io.StdIn.readLine

object Main extends App {

  val d = readLine.toInt

  val result = d match {
    case 25 => "Christmas"
    case 24 => "Christmas Eve"
    case 23 => "Christmas Eve Eve"
    case 22 => "Christmas Eve Eve Eve"
    case _ => "else"
  }

  println(result)

}