#include <cmath>
#include <cstring>
#include <iostream>
#include <limits>
#include <stdlib.h>
#include <string.h>
#include <stddef.h>
#include <limits.h>
#include <stdint.h>
#include <ctype.h>
#include <map>
#include <math.h>
#include <vector>
#include <set>

using namespace std;

using ll = long long;


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

    int n;
    cin >> n;

    long long nums[n];
    for (int i = 0; i < n; ++i) {
        cin >> nums[i];
    }

    long long result = 0;
    int bits = 0;

    for (int bit = 0; bit < 63; ++bit) {
        int mask = 1 << bit;

        for (int num : nums) {
            if ((num & mask) != 0) {
                bits += 1;
            }
        }

        if (bits >= 1) {
            result |= mask;
        }

        bits /= 2;
    }

    cout << result << endl;

    return 0;
}