#include <iostream>
#include <math.h>
#include <vector>
#include <algorithm>

int main() {
    int n;
    std::cin>>n;

    std::vector<unsigned long long> A(n);
    std::vector<unsigned long long> ASums(n+1);
    ASums[0] = 0;
    for(int i = 0; i < n; i++) {
        std::cin>>A[i];
        ASums[i+1] += ASums[i] + A[i];
    }

    unsigned long long res = 0;
    for(int l = 1; l <= n; l++) {
        for(int r = l; r <= n; r++) {
            res |= ASums[r] - ASums[l-1];
        }
    }

    std::cout<<res<<'\n';
}