import java.util.Scanner

val sc = Scanner(System.`in`)
val a = sc.nextInt()
val b = sc.nextInt()
val c = sc.nextInt()
val d = sc.nextInt()
val e = sc.nextInt()
val k = sc.nextInt()

fun main(args: Array<String>) {
    val ary = arrayListOf(a,b,c,d,e)
    val min = ary.min()
    val max = ary.max()

    print(if (k >= max!! - min!!) "Yay!" else ":(")
}