S = gets.strip
i=0
S.chars do |s|
    if i%2==0
        if s=="R" || s=="U" || s=="D"

        else
            puts 'No'
            exit
        end
    else
        if s=="L" || s=="U" || s=="D"

        else
            puts 'No'
            exit
        end

    end
    i+=1
end

puts 'Yes'
