words = gets.chomp.split('').to_a
odd_words = words.select.with_index { |_, i| i.even? }
even_words = words.select.with_index { |_, i| i.odd? }

if odd_words.include?("L")
  puts "No"
elsif even_words.include?("R")
  puts "No"
else
  puts "Yes"
end