array = gets.chomp.split('')

flag = "Yes\n"

array.each_with_index do |s, i|
  if (i+1) % 2 == 1
    if !'RUD'.include?(s)
      flag =  "No\n"
    end
  elsif (i+1) % 2 == 0
    if !'LUD'.include?(s)
      flag =  "No\n"
    end
  end
end

print flag
