def main(argv)
  s = gets.chomp
  
  x = ['RUD'.split(''), 'LUD'.split('')]
  
  flag = true
  s.split('').each_with_index do |c, i|
    if x[i % 2].find_index(c) === nil then
      flag = false
    end
  end
  
  puts (flag ? 'Yes' : 'No')
end

if self.to_s == 'main' then
  main(ARGV)
end