object Main extends App {

  val a = io.StdIn.readLine.toInt
  val b = io.StdIn.readLine.toInt
  val c = io.StdIn.readLine.toInt
  val d = io.StdIn.readLine.toInt
  val e = io.StdIn.readLine.toInt
  val k = io.StdIn.readLine.toInt

  val s = Seq(a,b,c,d,e)

  var isNG = false
  for (i <- 0 until s.size ; j <- i+1 until s.size) {
    if (s(j) - s(i) > k) isNG = true
  }

  if (isNG)
    println(":(")
  else
    println("Yay!")
}
