program main
  implicit none
  integer i, N, ans
  character(100) S
  read(*, *) S
  ans = 1
  !read(*, *) (L(i), i = 1,N)
  N = len(trim(S))
  do i = 1,N
    if (mod(i,2) == 1 .and. S(i:i) == 'L') then
      ans = 0
    else if (mod(i,2) == 0 .and. S(i:i) == 'R') then
      ans = 0
    endif
  end do
  if (ans == 0) then
    write(*, *) 'No'
  else
    write(*, *) 'Yes'
  end if
end program main
