axises = (1..5).map {gets.to_i}
k = gets.to_i
dists = []
axises.each_with_index do |a, i|
  axises.each_with_index do |b, j|
  	next if i == j
  	dists << (a - b).abs
  end
end
if dists.all? {|x| x <= k}
  puts 'Yay!'
else
  puts ':('
end