        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]
          	puts k>(max-min)?"Yay!":":(" 
        end
        main()