#include <iostream>
#include <vector>
#include <queue>
using namespace std;
using ll = long long;
void solve() {
	ll N;cin >> N;
	if (__builtin_popcount(N) == 1) {

		cout << -1 << endl;
		return;
	}
	int K = 35;
	ll res = 0;
	for (int i = 0;i < K;i++) {
		if (N & (1LL << i)) {
			res |= (1LL << i);
			for (int k = i+1;k < K;k++) {
				if (N & (1LL << k)) break;
				res |= (1LL << k);
			}
			cout << res << endl;
			return;
		}
	}

}
int main() {
	int t;cin >> t;
	while (t--) solve();
}