Step = gets.chomp

# print Step

Step.each_char.with_index{
  |c,i|
  # print c,' '
  if (i+1) % 2 == 1 then
    if c == 'L' then
      print 'No'
      exit
    end
  elsif c == 'R' then
      print 'No'
      exit
  end
}
    
print 'Yes'