array = gets.chomp.split('')

flag = "Yes\n"

array.each_with_index do |s, i|
  if i+1 % 2 == 1 && s == 'L'
    flag =  "No\n"
  elsif i+1 % 2 == 2 && s == 'R'
    flag =  "No\n"
  end
end

print flag
