fun main(args: Array<String>) {
    val p = Array(5) {
        readLine()!!.toInt()
    }
    val k = readLine()!!.toInt()

    println(if(f(p, k)) "Yay!" else ":(")
}

private fun f(p: Array<Int>, k: Int) : Boolean {
    var size = p.size
    for (i in 0..size-1) {
        for (j in (i+1)..size-1) {
            if (p[j] - p[i] > k) {
                return false
            }
        }
    }

    return true
}