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

template <typename T>
ostream& operator<< (ostream& os, const vector<T> & v) {
    os << "[ ";
    for (const T & elem : v) {
        os < elem << " ";
    }
    os << " ]";
    return os;
}

void test_case() {
    ll n;
    cin >> n;
    vector<ll> a(n);
    for (ll i = 0; i < n; ++i)
        cin >> a[i];
    
    vector<ll> one_bits(70, 0);
    for (ll i = 0; i < n; ++i) {
        
        ll curr = a[i];
        ll curr_bit = 0;
        while (curr) {
            one_bits[curr_bit] += curr % 2;
            curr /= 2;
            curr_bit++;
        }
    }
    // for (auto x : one_bits)
    //     cout << x << " ";
    // cout << endl << endl;

    for (ll i = 0; i < 69; ++i) {
        one_bits[i + 1] += one_bits[i] / 2;
    }

    // for (auto x : one_bits)
    //     cout << x << " ";
    // cout << endl;

    ll result = 0;
    ll curr_pow_2 = 1;
    for (ll i = 0; i < 70; ++i) {
        if (one_bits[i]) {
            result += curr_pow_2;
        }
        curr_pow_2 *= 2;
    }
    cout << result << endl;
}

int main() {
    cin.tie(0);
    cout.tie(0);
    cin.exceptions(ios::failbit);
    ios::sync_with_stdio(false);
    ll t = 1;
    //cin >> t; // potential comment
    while (t--) {
        test_case();
    }
    return 0;
}