a = gets.to_i
b = gets.to_i
c = gets.to_i
d = gets.to_i
e = gets.to_i
k = gets.to_i
arr = [a,b,c,d,e]

def five_antennas(arr, k)
  for i in 0..3 do
    for j in i+1..3
      if (arr[j] - arr[i]) > k
        return ":("
      end
    end
  end
  "Yay!"
end

puts five_antennas(arr, k)
