a,b,c,d,e,k = gets.split(" ").map(&:to_i)
ar = [a,b,c,d,e].combination(2).to_a
f = true
ar.each do |ar|
  r = ar[1].to_i - ar[0].to_i
  if r.abs > k
    p ":("
    f = false
    exit
  end
end
p "Yay!" if f