/*
	www.youtube.com/YugiHackerChannel
	linktr.ee/YugiHacker
*/
#include<bits/stdc++.h>
#define el cout<<"\n"
#define f0(i,n) for(int i=0;i<n;++i)
#define f1(i,n) for(int i=1;i<=n;++i)
#define maxn
using namespace std;

main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    int n;
    vector <int> cnt(64);
    cin >> n;
    long long g = 0;
    f1 (i, n) {
        int x; cin >> x;
        int d = __lg(x & -x);
        cnt[d]++;
        x /= x & - x;
        g = __gcd(g, 1ll * x);
    }
    int ans = 0;
    for (int i=0; i<63; i++) {
        cnt[i+1] += cnt[i] / 2;
        cnt[i] %= 2;
        if (cnt[i]) {
            for (int j=i+1; j<63; j++) if (cnt[j]) {
                cnt[i+1]++;
                cnt[j]--;
                cnt[i]--;
            }
        }
    }
    for (int i=0; i<63; i++) if (cnt[i] == 1) ans = i;
    cout << (1ll << ans) * g;
}