fun main(args:Array<String>) {
  val a = (1..5).map { readLine()!!.toInt() }.toTypedArray()
  val k = readLine()!!.toInt()
  println(if (solve(a, k)) "Yay!" else ":(")
}

fun solve(a:Array<Int>, k:Int) : Boolean {
  for ((index, value) in a.withIndex()) {
    for (i in index..a.size - 1) {
      if (a[index] - a[i] > k || a[i] - a[index] > k) {
        return false
      }
    }
  }
  return true
}
