#include <vector>
#include <iostream>
#include <string>

using namespace std;

//int a[100'000];
//int result = 0;

//void recursion(int idx) {
//		
//}

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

	int n;
	cin >> n;

	long long result = 0, sum = 0;
	long long in;
	for (int i = 0; i < n; ++i) {
		cin >> in; //a[i];
		result |= in;
		sum += in;
	}
	result |= sum;
	cout << result << "\n";
	

	return 0;
}