input = readlines.map &:chomp
 
limit = input[5].to_i
 
number_list = []
 
[*(0..4)].each do |number|
  number_list.push(input[number].to_i)
end 

max= number_list.max
min = number_list.min
 
if (max - min) > limit 
  puts ':('
else 
  puts 'Yay!'
end 