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

int n, k = 0;
long long a;

int main(){
    cin >> n;
        
    for(int i = 0; i < n; i++){
        cin >> a;
        
        while(a & (1ull << k))
            k++;
    }
    
    cout << (1ull << k) << endl;
}