#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<ll>;

void fun(ll num, vi& ones) {
    for (ll i = 0; i < 64; ++i) {
        ll del = 1ll << i;
        ll ans = num / del;
        ones[i] += (ans & 1);
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    ll n;
    cin >> n;
    vi a(n);
    vi ones(64);

    for (ll& x : a) {
        cin >> x;
        fun(x, ones);
    }

    for (ll i = 1; i < 64; ++i) {
        ones[i] += ones[i - 1] / 2;
    }

    ll answer = 0;
    for (ll i = 0; i < 64; ++i) {
        if (ones[i] >= 1) {
            answer += (1ll << i);
        }
    }

    cout << answer << '\n';

    return 0;
}