object Main extends App {
	val a = new Array[Int](5)

	for(i<-0 until 5){
		a(i) = scala.io.StdIn.readInt
	}

	val k = scala.io.StdIn.readInt

	var flag = true

	for(i<-0 to 3){
		for(j<-i to 4){
			if((a(j) - a(i)).abs > k) flag = false
		}
	}

	if(flag) println("Yay!")
	else println(":(")

}