open System

[<EntryPoint>]
let main argv =
    let a = Console.ReadLine() |> int
    let b = Console.ReadLine() |> int
    let c = Console.ReadLine() |> int
    let d = Console.ReadLine() |> int
    let e = Console.ReadLine() |> int
    let k = Console.ReadLine() |> int
    if (b - a) <= k && (c - b) <= k && d - c <= k && e - d <= k then "Yay!" else ":("
    |> Console.WriteLine
    0