#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#include <map>
#include <complex>
#include <iomanip>
#include <cmath>
#include <string>
#include <queue>
#include <stack>
#include <cstring>
#include <set>

#define ll long long
#define ld long double
#define HS ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define INF 1e15
#define point complex <double>
#define all(a) a.begin(), a.end()
#define pi acos(-1)
#define file  freopen("input.txt", "r", stdin);freopen("output.txt", "w", stdout);

using namespace std;

int main()
{
    HS;
    int n;
    cin>>n;
    ll arr[n+5];
    for(int i=0;i<n;i++)
        cin>>arr[i];
    ll mini=INF;
    for(int i=0;i<(1<<n);i++)
    {
        ll xr=0;
        ll orr=0;
        for(int j=0;j<n;j++)
        {
            if(i & (1<<j))
            {
                xr^=orr;
                orr=0;
            }

            orr|=arr[j];
        }
        xr^=orr;
        mini=min(mini,xr);

    }
    cout << mini << endl;


    return 0;
}

#include <iostream>
#include <bits/stdc++.h>
using namespace std;
typedef  long long int ll;
typedef long double db;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template <typename T>
using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define pll pair<ll,ll>
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define ub(v,val) upper_bound(v.begin(),v.end(),val)
#define np(str) next_permutation(str.begin(),str.end())
#define lb(v,val) lower_bound(v.begin(),v.end(),val)
#define sortv(vec) sort(vec.begin(),vec.end())
#define rev(p) reverse(p.begin(),p.end());
#define v vector
#define len length()
#define repc(i,s,e) for(ll i=s;i<e;i++)
#define fi first
#define se second
#define mset(a,val) memset(a,val,sizeof(a));
#define mt make_tuple
#define repr(i,n) for(i=n-1;i>=0;i--)
#define rep(i,n) for(i=0;i<n;i++)
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define at(s,pos) *(s.find_by_order(pos))
#define set_ind(s,val) s.order_of_key(val)
long long int M = 1e9 + 7 ;
long long int inf = 9 * 1e18;
const double PI = acos(-1);
//CLOCK
ll begtime = clock();
#define time() cout << "\n\nTime elapsed: " << (clock() - begtime)*1000/CLOCKS_PER_SEC << " ms\n\n";
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//CLOCK ENDED
ll n, m;
// modular exponentiation
ll binpow(ll val, ll deg)
{
	if (deg < 0)
		return 0;
	if (!deg)
		return 1 % M;
	if (deg & 1)
		return binpow(val, deg - 1) * val % M;
	ll res = binpow(val, deg >> 1);
	return (res * res) % M;
}
//binomial
ll modinv(ll n) {
	return binpow(n, M - 2);
}
// void out(ll x) {
// 	cout << "Case #" << x << ": ";
// }

int main() {
	// your code goes here
	IOS;
#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif
	ll i, j, t, k, x, y, z,	  N;
	cin >> n;
	ll a[n];
	rep(i, n) cin >> a[i];

	ll ans = inf;

	rep(i, (1ll << (n - 1))) {
		k = i | (1 << (n - 1));

		ll xorr = 0;
		ll orr = 0;
		rep(j, n) {
			orr |= a[j];
			if ((1 << j)&k) {
				xorr ^= orr;
				orr = 0;
			}
		}
		// cout << k << ' ';
		ans = min(ans, xorr);
	}
	cout << ans;
	return 0;


}




