S = gets.chomp.split("")

for i in 0...S.length do
  if (i + 1).even? && S[i] == 'R' then
    puts 'No'
    break
  elsif (i + 1).odd? && S[i] == 'L' then
    puts 'No'
    break
  elsif (i + 1) == S.length then
    puts 'Yes'
  end
end