import java.util.*

fun main(args: Array<String>) {
  val sc = Scanner(System.`in`)
  val a = sc.nextInt()
  val b = sc.nextInt()
  val c = sc.nextInt()
  val d = sc.nextInt()
  val e = sc.nextInt()
  val k = sc.nextInt()

  val array = IntArray(5) { 0 }
  array[0] = a
  array[1] = b
  array[2] = c
  array[3] = d
  array[4] = e
  

  val dist = mutableListOf<Int>()
  for (i in 0..3) {
    for (j in i+1..4) {
      val tmp = array[j] - array[i]
      dist.add(tmp)
    }
  }

  val has = dist.any { it > k }
  if (has) {
    println(":(")
    return
  }
  println("Yay!")
}
