Note.ms

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

#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define fi first
#define se second
const int N = 2e5 + 5, M = 1e6 + 5;
const int inf = 1e9, mod = 998244353;
const ll INF = 1e18, wxhn = 2324814;
mt19937 rd(time(0));
uniform_int_distribution<int> dist(0, wxhn);

struct qwq{
	vector <int> a;

void init(string s){
		reverse(s.begin(), s.end());
		a.clear();
		for (auto i : s) a.push_back(i - '0');
	}
	void init(int x){
		a.clear();
		if (!x) a.push_back(0);
		while (x) a.push_back(x % 10), x /= 10;
	}
	void read(){
		string awa; cin >> awa;
		init(awa);
	}
	const qwq operator += (const qwq &rr){
		vector <int> x = rr.a;
		while (a.size() < x.size()) a.push_back(0);
		for (int i = 0; i < x.size(); i ++ ) a[i] += x[i];
		for (int i = 0; i < a.size(); i ++ ){
			if (a[i] > 9){
				if (i + 1 >= a.size()) a.push_back(a[i] / 10);
				else a[i + 1] += a[i] / 10;
				a[i] %= 10;
			}
		}
		return (*this);
	}
	const qwq operator -= (const qwq &rr){
		vector <int> x = rr.a;
		for (int i = 0; i < x.size(); i ++ ) a[i] -= x[i];
		for (int i = 0; i < a.size(); i ++ ){
			while (a[i] < 0){
				a[i + 1] -= 1;
				a[i] += 10;
			}
		}
		while (a.size() && a.back() == 0) a.pop_back();
		if (!a.size()) a.push_back(0);
		return (*this);
	}
	const qwq operator -= (const int &x){
        // cout << a[0] << " " << x << " " << a[0] - x << "\n";
		a[0] -= x;
		for (int i = 0; i < a.size(); i ++ ){
			if (a[i] < 0){
				a[i + 1] -= 1;
				a[i] += 10;
			}
		}
		while (a.size() && a.back() == 0) a.pop_back();
		if (!a.size()) a.push_back(0);
		return (*this);
	}
	const qwq operator += (const int &x){
		a[0] += x;
		for (int i = 0; i < a.size(); i ++ ){
			if (a[i] > 9){
				if (i + 1 >= a.size()) a.push_back(a[i] / 10);
				else a[i + 1] += a[i] / 10;
				a[i] %= 10;
			}
		}
		return (*this);
	}
	const qwq operator /= (const int &x){
		int r = 0;
		vector <int> vec;
		for (int i = a.size() - 1; i >= 0; i -- ){
			r *= 10, r += a[i];
			vec.push_back(r / x);
			r %= x;
		}
		reverse(vec.begin(), vec.end());
		a = vec;
		while (a.size() && a.back() == 0) a.pop_back();
		if (!a.size()) a.push_back(0);
		return (*this);
	}
	const bool operator < (const qwq &rr){
		vector <int> x = rr.a;
		if (a.size() < x.size()) return true;
		if (a.size() > x.size()) return false;
		for (int i = a.size() - 1; i >= 0; i -- ) if (a[i] != x[i]) return a[i] < x[i];
		return false;
	}
	const bool operator <= (const qwq &rr){
		vector <int> x = rr.a;
		if (a.size() < x.size()) return true;
		if (a.size() > x.size()) return false;
		for (int i = a.size() - 1; i >= 0; i -- ) if (a[i] != x[i]) return a[i] < x[i];
		return true;
	}
	const bool operator == (const qwq &rr){
		return a == rr.a;
	}
} k, len, sum, sta, one, thr;

void print(qwq x){
	for (int i = x.a.size() - 1; i >= 0; i -- ) cout << x.a[i];
	cout << "\n";
}

signed main(){
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    one.init(1), thr.init(3);

int n;
    while (cin >> n){
    	k.read();

if (n == 1){
    		if (one < k) cout << "-1\n";
    		else cout << "1\n";
    		continue;
    	}
    	if (n == 2){
    		if (thr < k) cout << "-1\n";
    		else print(k);
    		continue;
    	}
    	if (n == 3){
    		int md = 0;
    		for (auto i : k.a) md = (md + i) % 3;
    		k -= 1, k /= 3, k += 1;

qwq res; res.init(1);
    		while (k.a.size() > 1 || k.a[0] > 0){
                res += res, k -= 1;
            }

if (md == 0) res += 1;
    		else if (md == 1) res -= 1;
    		print(res);
    		continue;
    	}

len.init(n);
    	sum.init(n);
    	sta.init(1);

while (sum < k){
    		len += len, len += 3;
    		sum += len;
    		sta += sta, sta += 1;
    	}

sum -= len;
    	qwq lst = k; lst -= sum, lst -= 1;
    	sta += lst;
    	print(sta);
    }
}

Note.ms/shit