#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using namespace std;
using ll=long long;
using ld=double;
ld pie=3.14159265359;
ll mod=998244353;
long long inf=100000000000000001;
int main(){
    ll n;
    cin >> n;
    vector<ll>a(n);
    for (ll i = 0; i < n; i++)
    {
        cin >> a[i];
    }
    vector<ll>two(17,1);
    for (ll i = 1; i <=16; i++)
    {
        two[i]=two[i-1]*2;
    }
    if (n>=16)
    {
        ll ans=0;
        for (ll i = 0; i < 16; i++)
        {
            ans+=two[i];
        }
        cout << ans << endl;
        return 0;
    }
    ll dai=0;
    for (ll i = 0; i < 16; i++)
    {
        dai+=two[i];
    }
    vector<vector<ll>>dp(n+1,vector<ll>(dai+10,0));
    dp[0][0]=1;
    for (ll i = 0; i < n; i++)
    {
        vector<ll>b;
        for (ll j = 0; j < 16; j++)
        {
            b.push_back(a[i]);
            if (a[i]%2)
            {
                a[i]+=two[16];
            }
            a[i]/=2;
        }
        for (ll j = 0; j <= dai; j++)
        {
            for (ll k = 0; k < b.size(); k++)
            {
                ll x=j;
                x=x|b[k];
                dp[i+1][x]+=dp[i][j];
            }
        }
    }
    ll ans=0;
    for (ll i = 0; i < dp[n].size(); i++)
    {
        if (dp[n][i]>=1)
        {
            ans=i;
        }
    }
    cout << ans << endl;
}