line = gets.chomp.split("")

ans = "Yes"
line.each_with_index do |pos, i|
    if (i + 1) % 2 == 0 and pos == "R"
        ans = "No"
    end
    if (i + 1) % 2 == 1 and pos == "L"
        ans = "No"
    end
end

puts ans
