#include<bits/stdc++.h>
#include<atcoder/all>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
using namespace atcoder;
typedef long long ll;
typedef pair<int, int> P;

template <int m> ostream& operator<<(ostream& os, const static_modint<m>& a) {os << a.val(); return os;}
template <int m> ostream& operator<<(ostream& os, const dynamic_modint<m>& a) {os << a.val(); return os;}
template <int m> istream& operator>>(istream& is, static_modint<m>& a) {long long x; is >> x; a = x; return is;}
template <int m> istream& operator>>(istream& is, dynamic_modint<m>& a) {long long x; is >> x; a = x; return is;}
template<typename T> istream& operator>>(istream& is, vector<T>& v){int n = v.size(); assert(n > 0); rep(i, n) is >> v[i]; return is;}
template<typename U, typename T> ostream& operator<<(ostream& os, const pair<U, T>& p){os << p.first << ' ' << p.second; return os;}
template<typename T> ostream& operator<<(ostream& os, const vector<T>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : " "); return os;}
template<typename T> ostream& operator<<(ostream& os, const vector<vector<T>>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : ""); return os;}
template<typename T> ostream& operator<<(ostream& os, const set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;}
template<typename T> ostream& operator<<(ostream& os, const unordered_set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;}
template<typename S, auto op, auto e> ostream& operator<<(ostream& os, const atcoder::segtree<S, op, e>& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;}
template<typename S, auto op, auto e, typename F, auto mapping, auto composition, auto id> ostream& operator<<(ostream& os, const atcoder::lazy_segtree<S, op, e, F, mapping, composition, id>& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;}

template<typename T> void chmin(T& a, T b){a = min(a, b);}
template<typename T> void chmax(T& a, T b){a = max(a, b);}

int main(){
	long long n, m;
	cin >> n >> m;
	long long ans = 0;
	vector<pair<long long, long long>> vec;
	vec.emplace_back(0LL, n);
	for(int k = 29; k >= 0; k--){
		long long x = (1LL << k);
		
		vector<pair<long long, long long>> vec_next;
		long long rest = -1;
		
		sort(vec.begin(), vec.end());
		for(auto [val, num] : vec){
			if(val + x <= m){
				if(rest == -1){
					if(num % 2){
						long long t = num / 2;
						if(t > 0){
							ans += x * (2 * t);
							vec_next.emplace_back(val + x, 2 * t);
						}
						rest = val;
					}else{
						long long t = num / 2;
						if(t > 0){
							ans += x * (2 * t);
							vec_next.emplace_back(val + x, 2 * t);
						}
						rest = -1;
					}
				}else{
					if(num % 2){
						long long t = num / 2 + 1;
						if(t > 0){
							ans += x * (2 * t);
							vec_next.emplace_back(val + x, 2 * t - 1);
							vec_next.emplace_back(rest + x, 1);
						}
						rest = -1;
					}else{
						long long t = num / 2;
						if(t > 0){
							ans += x * (2 * t);
							vec_next.emplace_back(val + x, 2 * t - 1);
							vec_next.emplace_back(rest + x, 1);
						}
						rest = val;
					}
				}
			}else{
				vec_next.emplace_back(val, num);
			}
		}
		if(rest != -1){
			vec_next.emplace_back(rest, 1LL);
		}
		vec = vec_next;
		cerr << vec;
		cerr << ans << "\n";
	}
	if(n % 2 == 0){
		assert(ans == n * m);
	}
	cout << ans << "\n";
	return 0;
}