#include <bits/stdc++.h>
using namespace std;
#define rep(i, a, b) for (int i = (a); i < (b); i++)
#define fo(i, n) rep(i, 0, n)
#define all(x) std::begin(x), std::end(x)
#define sz(x) int((x).size())
#define F first
#define S second
#define MP make_pair
#define PB push_back
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef vector<vi> vvi;
typedef vector<pii> vpii;
typedef vector<ll> vll;
typedef pair<ll, ll> pll;
typedef vector<vll> vvll;
typedef vector<pll> vpll;

signed main()
{
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.badbit | cin.failbit);

    ll mask = 0;
    ll s = 0;
    ll n;
    cin >> n;
    fo(__, n) {
        ll v;
        cin >> v;
        mask |= v;
        s += v;
        mask |= s;
    }

    cout << mask << endl;
}