How may I perform such operation on bitset, taking advantage of bitset speedup?

It is quite frustrating because such a thing is trivial to implement for a bitset, but designer of std::bitset interface does not allow so.

Because my rating is not high enough I cannot have a public gym. But I want to add my problem to vJudge. How can I do it? The only way I can think of is inviting the Vjudge crawler to my contest. But I do not know their username. Please help and thank you.