s = gets.chomp

s.chars.each_with_index do |char, i|
  if i%2 == 0
    unless ["R", "U", "D"].include?(char)
      puts "No"
      exit
    end
  else
    unless ["L", "U", "D"].include?(char)
      puts "No"
      exit
    end
  end
end

puts "Yes"
