    def main()
      	array = []
    	STDIN.each_line {|line|
      		array.push(line.chomp)
        }
      	array = array.map {|n| n.to_i }
          k = array.pop()
                  p array

          a = array.minmax()
          min = a[0]
          max = a[1]
      	print k>(max-min)?"Yay!":":(" 
    end
    main()