#include <iostream>
#include <cstdint>

using namespace std;

int main()
{
	cin.tie(nullptr);
	ios::sync_with_stdio(false);

	uint32_t N, M;
	cin >> N >> M;

	uint64_t ans = 0;
	if (N <= 31 && M >= (1u << (N - 1))) cout << (1u << N) - 1 << '\n';
	else
	{
		for (; N != 0 && M != 1; --N, M = (M + 1) >> 1)
			ans += M;

		cout << ans + N << '\n';
	}
	return 0;
}