object Main extends App {
  import scala.io.StdIn.readLine

  val d = readLine().toInt
  var res = ""
  if (d == 25) {
    res = "Christmas"
  } else if (d == 24) {
    res = "Christmas Eve"
  } else if (d == 23) {
    res = "Christmas Eve Eve"
  } else if (d == 22) {
    res = "Christmas Eve Eve Eve"
  }

  println(res)
}