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