program main
  
  implicit none
  character(100) :: s
  integer :: i,j,k,n
  
  read(*,*) s
  n = len_trim( s )
  
  j = 0
  do i = 1, n
    if ( mod(i,2) == 0 ) then
      if ( s(i:i) == "R" ) then
        print*, "No" 
        j = 1
        exit
      end if
    else
      if ( s(i:i) == "L" ) then
        print*, "No" 
        j = 1
        exit
      end if
    end if
  end do
  if( j == 0 ) print*, "Yes" 
end program main
