#include <vector>
#include <array>
#include <cstdio>

#define ull unsigned long long

using namespace std;

int main() {
	int n;
	scanf("%d", &n);

	array<ull, 64> arr;

	arr.fill(0);


	for (int i = 0; i < n; ++i) {
		//for (int x = 0; x < 64; ++x) { printf("%lld ", arr.at(x)); } puts("");

		ull v;
		scanf("%lld", &v);

		for (int i = 0; i < 64; ++i) {
			if ((v & 1) == 1) {
				arr[i] += 1;
			}
			v = v >> 1;
		}
	}

	//puts("==============");

	ull possible = 0;

	//for (int i = 0; i < 64; ++i) {
		//auto len = 64 -__builtin_clzll((ull)i);
		//printf("X: %d %d %d\n", i, len, (1 << len)-1);
	//}

	for (int i = 0; i < 64; ++i) {
		if (arr[i] != 0) { possible |= 1 << i; }

		//printf("%d %lld %lld\n      ", i, arr[i], possible);
		//for (int x = 0; x < 10; ++x) { printf("%lld ", arr.at(x)); } puts("");

		auto len = 64 -__builtin_clzll(arr[i]);
		if (arr[i] > 0)
			possible |= ((1 << len) - 1) << i;

		ull curr = arr[i] >> 1;

		for (int j = i+1; j < 10; ++j) {
			//printf("         %lld\n", curr);
			if ((curr & 1) == 1) arr[j] += 1;
			curr = curr >> 1;
		}
	}


	printf("%lld\n", possible);
}