s = gets.chomp("")

easy = true
(s.length).times do |i|
  if (i+1)%2 != 0
    if s[i] == "L"
      easy = false
      break
    end
  else
    if s[i] == "R"
      easy = false
      break
    end
  end
end

if easy
  puts "Yes"
else
  puts "No"
end
