def main()
  	array = []
	STDIN.each_line {|line|
  		[].push(line)
	}
  	array = array.map {|n| n.to_i }
  	k = array.pop()
  	min = array.min()
  	max = array,max()
  	print k<=max-min?"Yay!":":(" 
end
main()