s = gets.chop.to_s

i = 1
ret = true
s.chars {|ch|
  if ch.match(/[UD]/)
  elsif i % 2 == 1 and ch.match(/R/)
  elsif i % 2 == 0 and ch.match(/L/)
  else
    ret = false
  end

  if !ret
    break
  end

  i += 1
}

if ret
  puts 'Yes'
else
  puts 'No'
end
