#include <bits/stdc++.h>

using namespace std;

#define INF 10000000007
#define DIM 100007
#define endl '\n'
#define sp " "

using ll = long long;
using ld = long double;
using pll = pair<ll,ll>;
using str = string;

ll n, a[DIM];

map<ll, ll> m;
int main(){

    cin>>n;
    for(int i=1;i<=n;i++) {
        cin>>a[i];
        m[0]+=a[i]%2;
        a[i]-=a[i]%2;
    }
    
    ll check = pow(2, 60); ll p = 60;
    while(p>0) {
        for(int i=1;i<=n;i++) {
            if(a[i]>=check) {
                m[p]++;
                a[i]-=check;
            }
        }
        check/=2; p--;
    }
    ll res = 0;
    for(auto x:m) {
        res += pow(2, x.first);
        if(x.second>1) {
            m[x.first+1]++;
        }
    }
    cout<<res<<endl;
    return 0;
}