s_array = gets.chomp.split("")

ret = "Yes"
s_array.each_with_index do |e, i|
    if i.odd?
        if !["L", "U", "D"].include?(e)
            ret = "No"
            break
        end
    else
        if !["R", "U", "D"].include?(e)
            ret = "No"
            break
        end
    end
end

puts ret