#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
#include <queue>
#include <map>
#include <cmath>
#include <iomanip>
#include <cstdio>

using namespace std;

const int INF = 1001001001;

int main() {
    int n;
    cin >> n;
    vector<long long> a(n);
    long long sum = 0;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
        sum |= a[i];
    }
    long long x = 1;
    for (int i = 0; i < 60; i++) {
        if (sum % 2 == 0) {
            cout << x << endl;
            return 0;
        } else {
            x *= 2;
            sum /= 2;
        }
    }
    return 0;
}