s = gets.chop

flag = 1

for i in 0..s.length-1 do

  if i % 2 == 0 && s[i] == 'L' then
    flag = 0
  end

  if i % 2 == 1 && s[i] == 'R' then
    flag = 0
  end

end


if flag == 1 then
  puts "Yes"
else
  puts "No"
end
