program test
implicit none
integer::i,n,check
character::S*100
check=0
read*,S
S=trim(S)
n=len(S)
do i=1,n
	if(mod(i,2)==1)then
    	if(S(i:i)=='L')then
        	check=check+1
         else 
         	check=check
         end if
    else 
    	if(S(i:i)=='R')then
        	check=check+1
         else 
         	check=check
         end if
    end if
end do
if(check==0)then 
	print*,'Yes'
else 
	print*,'No'
end if
end program test