program main
integer :: ans = 0
character*100 :: s
read(*,*)s
s = trim(s)
do i = 1,len(s)
if (mod(i,2)==1) then
if (s(i:i) == 'L') ans = 1
else
if (s(i:i) == 'R') ans = 1
end if
end do
if (ans == 0) then
write(*,*)'Yes'
else
write(*,*)'No'
end if
end program