program main
  implicit none
  integer a, b, c, d, e, k
  read(*, *) a
  read(*, *) b
  read(*, *) c
  read(*, *) d
  read(*, *) e
  read(*, *) k
  if (e-a > k) then
    write(*, '(A)') ':('
  else
    write(*, '(A)') 'Yay!'
  end if
end program main