#!/usr/bin/ruby
#encoding: utf-8

s = gets.chomp

evenFlg = true
oddFlg = true

(0..s.size-1).each do |i|
  if i.even?
    if s[i] == 'L'
      oddFlg = false
      break
    end
  else
    if s[i] == 'R'
      evenFlg = false
      break
    end
  end
end

if oddFlg & evenFlg == true
  puts "Yes"
else
  puts "No"
end