#include <iostream>
#include <cstdint>
#include <vector>

using namespace std;


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;
    uint64_t out = 0, sum = 0;
    for (int i = 0; i < n; i++) {
        int j;
        cin >> j;
        out |= j;
        sum += j;
        out |= sum;
    }

    cout << out << '\n';

    return 0;
}