s = gets.strip

s.length.times do |i|
  if(s[i] == "L" && i % 2 == 0)
    puts "No"
    break
  elsif(s[i] == "R" && i % 2 != 0)
    puts "No"
    break
  end
  
  if(i == s.length - 1)
    puts "Yes"
  end
end