S = gets.chomp

S.each_char.with_index do |s, i|
    if i % 2 == 0
        unless ["R", "U", "D"].include?(s)
            puts "No"
            exit
        end
    else
        unless ["L", "U", "D"].include?(s)
            puts "No"
            exit
        end
    end
end

puts "Yes"