s = gets.chomp.split(//)

$fumi = "Yes"
catch(:break_loop) do
    s.each_with_index do |step,index|
        if (index+1).odd?
            ($fumi = "No" ; throw :break_loop) if step == "L" 
        elsif (index+1).even?
            ($fumi = "No" ; throw :break_loop) if step == "R"
        end
    end
end

puts $fumi