C++ :

#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#define ull unsigned long long
using namespace std;
const int maxn = 64 + 5;
ull n, k, p[maxn];
int main()
{
	cin >> n >> k;
	p[0] = 1;
	for(int i = 1; i <= n; ++ i) p[i] = p[i - 1] << 1ll;
	int cur = 0;
	for(int i = n; i > 0; -- i)
	{
		if(!cur)
		{
			if(k < p[i - 1]) 
			{
				putchar('0');
				cur = 0;
			}
			else 
			{
				putchar('1');
				cur = 1;
			}
		}
		else
		{
			if(k < p[i - 1]) 
			{
				putchar('1');
				cur = 0;
			}
			else 
			{
				putchar('0');
				cur = 1;
			}
		}
		k %= p[i - 1];
	}
	return 0;
}