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

void fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}

int main() {
    fast_io();
    int n;
    cin >> n;
    vector<long long> a(n);
    long long su = 0;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
        su |= a[i];
    }
    int ans = 0;
    while (su & (1LL << ans)) {
        ans++;
    }
    cout << (1LL << ans) << endl;
}