fun main(args: Array<String>) {
    var x = (1..6).map{
        readLine()!!.toInt()
    }
    var k = x[5]
    var flag = false
    
    for(i in 0..x.size-2){
        for(j in i+1..x.size-1){
            var d = x[j]-x[i]
            if(k<d) flag = true
        }
    }
    if(flag) println(":(")
    else println("Yay!")
}