az，这种$O(n^2)$的能过?$10^6$欸

#include <bits/stdc++.h>
using namespace std;
int a[1000005];
int main() {
	int n, maxx = 0;
	cin >> n;
	for (int i = 1; i <= n; i++)
		cin >> a[i];
	for (int i = 1; i <= n; i++)
		for (int j = 1; j <= n; j++)
			if (i ^ j)
				maxx = max(a[i] & a[j], maxx);
	cout << maxx;
	return 0;
}