fun main(args: Array<String>) {
    abc123a()
}

fun abc123a() {
    val antenna = (1..5).map { readLine()!!.toInt() }
    val distantLimit = readLine()!!.toInt()

    val maxDistant = antenna[4] - antenna[0]

    if (maxDistant <= distantLimit) println("Yay!") else println(":(")
}
