import java.util.Scanner

object Main extends App {
  val sc = new Scanner(System.in)

  val n = sc.nextInt

  def makeMap(): Map[String, Int] = {
    Map(
      "Red" -> 0,
      "Orange" -> 0,
      "Yellow" -> 0,
      "Green" -> 0,
      "Cyan" -> 0,
      "Blue" -> 0,
      "Violet" -> 0,
    )
  }

  var a = makeMap()
  for(col <- Array.fill(n)(sc.next)) {
    val t = a(col) + 1
    a += col -> t
  }
  for(col <- Array.fill(n - 1)(sc.next)) {
    val t = a(col) + 1
    a += col -> t
  }

  println(a.keys.filter(a(_) % 2 == 1).head)
}