program main

  implicit none
  character(len=100) S
  integer :: lnS, i

  read(*,*) S

  lnS = len(trim(S))

  ! check odd
  do i = 1,lnS,2
     if ( S(i:i) == "L") then
        write(*,'(a)') "No"
        stop
     end if
  end do
  ! check even
  do i = 2,lnS,2
     if ( S(i:i) == "R") then
        write(*,'(a)') "No"
        stop
     end if
  end do

  write(*,'(a)') "Yes"

end program main
