#coding: euc-jp
class Main
  def self.main
    min = 123
    max = 0
    5.times do
      a = read
      min = a if a < min
      max = a if a > max
    end
    k = read
    puts max - min <= k ? 'Yay!' : ':('
  end

  def self.read
    gets.chomp.to_i
  end
end

Main.main
