n = gets.chop.to_i
a = []
n.times { a << gets.to_i }

target = a[0...a.size - 1]
k = a.last
output = ''
 
a.each_with_index do |num, i|
  break if i == target.size
  output = ':(' if (target[i + 1] - num).abs > k
end
 
output = 'Yay!' if output.empty?
puts output
nums = gets.split("\n").to_i
target = n[0...n.size - 1]
k = n.last
output = ''

nums.each_with_index do |n, i|
  break if i == target.size
  output = ':(' if (target[i + 1] - n).abs > k
end

output = 'Yay!' if output.empty?
puts output
