#include <bits/stdc++.h>
using namespace std;
#define int long long

void solve() {
    vector<unsigned long long> counters(64);
    int n;
    cin >> n;
    for(int i = 0; i < n; i++) {
        unsigned long long num;
        cin >> num;
        for(int i = 0; num; i++, num >>= 1) {
            if(num & 1)
                counters[i]++;
        }
        /*
        for(int i = 63; i >= 0; i--)
            cout << counters[i];
        cout << endl;
        */
    }
    vector<bool> res(64);
    for(int i = 0; i < 63; i++) {
        if(counters[i] > 0)
            res[i] = true;
        counters[i + 1] += counters[i] / 2;
    }
    unsigned long long r = 0;

    for(int i = 63; i >= 0; i--) {
        r <<= 1;
        if(res[i])
            r |= 1;
    }

    cout << r << endl;
}

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int t = 1;
    while(t--) {
        solve();
    }
    return 0;
}