string = gets.chomp.split("")

flag = true
string.each.with_index do |char, index|
  if index % 2 == 0
    flag = false unless (char == 'R' || char == 'U' || char == 'D')
  else
    flag = false unless (char == 'L' || char == 'U' || char == 'D')
  end
end

if flag
  puts 'Yes'
else
  puts 'N0'
end