object Main{
  def main(args: Array[String]){
    if (sys.env.getOrElse("TEST", "")=="1"){

    }else{
      val input=io.Source.stdin.getLines().mkString("\n")
      println(solve(input).trim());
    }
  }


  def solve(input:String):String ={
    val nums = input.split("\n").map(_ .toInt)
    val limitRange = nums.last
    val aa = nums.dropRight(1)
	val ret= if ((aa.max - aa.min) <= limitRange){
    	"Yay!"
    } else {
      ":("
    }
    ret
  }
}