AC（规律题）

#include <bits/stdc++.h>
using namespace std;

int num[4] = {0, 1, 1, 0};

int main() {
	unsigned long long n, k;
	cin >> n >> k;
	for (unsigned long long i = n - 1; i > 0; i--) {
		cout << num[(k / ((unsigned long long)(1) << i)) % 4];

	}
	cout << num[k % 4];
	return 0;
}