gets.chomp.each_char.with_index do |s,i|
  if i%2==0
    unless [?R,?U,?D].include? s
      puts 'No'
      exit
    end
  else
    unless [?L,?U,?D].include? s
      puts 'No'
      exit
    end
  end
end
puts 'Yes'
