#include <bits/stdc++.h>

using namespace std;

using ll = unsigned long long;
#define all(x) begin(x), end(x)
#define rep(i,a,b) for (auto i = a; i < (b); ++i)
#define vi vector<int>
#define pii pair<int,int>

#define W(x) cerr << #x << ": " << (x) << "\n";

constexpr int BITS = 64;

int main () {
	cin.tie(0)->sync_with_stdio(0);

	array<ll, BITS> bits{};
	int n;
	vector<ll> nums;
	cin >> n;
	rep(i,0,n) {
		ll x;
		cin >>x;
		for (int i = 0; i < BITS; ++i) {
			if (x & (1ll << i))
				++bits[i];
			nums.push_back(x);
		}
	}

	// const char *sep = "";
	// for (auto x : bits) {
	// 	cerr << sep << x;
	// 	sep = ", ";
	// }
	// cerr << endl;

	ll acc = 0ll;
	for (int i = 0; i < BITS; ++i) {
		if (bits[i])
			acc |= (1ll << i);
		if (i + 1 < BITS)
			bits[i+1] += bits[i] / 2;
	}

	cout << acc << endl;

	return 0;
}