import java.util.Scanner

object Main {
  def main(args: Array[String]): Unit = {
    val sc = new Scanner(System.in)
    val D = Integer.parseInt(sc.next)
    
    println(
      if (D == 25) "Christmas"
      else if (D == 24) "Christmas Eve"
      else if (D == 23) "Christmas Eve Eve"
      else "Christmas Eve Eve Eve"
    )
  }
}