#include <iostream>
#include <vector>
using namespace std;
typedef long long ll;

signed main() {
    int n;
    std::cin >> n;
    vector<ll> nums(n);
    for(ll i = 0; i < n; i++) std::cin >> nums[i];

    vector<ll> counts(65);

    ll out = 0;
    for(ll i = 0; i < 64; i++) {
        for(ll j = 0; j < n; j++) {
            if((1 << i ) & nums[j]) counts[i]++;
        }
    }

    for(ll i = 0; i < 64; i++) {
        // cout << "Count " << i << " " << counts[i] << "\n";
        if(counts[i]) out |= (1 << i);
        counts[i+1] += counts[i]/2;
    }

    std::cout << out << endl;
}