ary = gets.split("")
k = 1
ary.each do |n|
    if n== "L" && k%2 == 1
        puts "No"
        break
    end
    if k%2 ==0 && n== "R"
        puts "No"
        break
    end
    k+=1
end

puts "Yes" if k-1 == ary.length