program tap_dance
  implicit none
  character(100) :: s
  integer :: n, i
  read(*,*) s
  n = len_trim(s)
  do i = 1, n
    if ((mod(i,2) == 1 .and. s(i:i) == "L") .or. &
    & (mod(i,2) == 0 .and. s(i:i) == "R")) then
      write(*,'(a)') "No"
      stop
    end if
  end do
  write(*,'(a)') "Yes"
end program tap_dance