      program answer
      implicit none
      character(len=1),dimension(100) :: S
      integer :: eof
      integer :: i
      intrinsic mod
      eof = 0
      read(*,'(100A)') (S(i),i=1,100)
      do i=1,100
        if( mod(i,2) == 1) then
          if( S(i) == 'L') then
            eof = 1
            exit
          end if
        else if( mod(i,2) == 0) then
          if( S(i) == 'R') then
            eof = 1
            exit
          end if
        end if
      end do
      if( eof == 0) write(*,'(A)') 'Yes'
      if( eof == 1) write(*,'(A)') 'No'
      stop
      end program answer