#include <bits/stdc++.h>
using namespace std;

using ll = long long;

bool chmin(auto &a, auto b) { return a > b ? a = b, true : false; }
bool chmax(auto &a, auto b) { return a < b ? a = b, true : false; }

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

    int T;
    cin >> T;
    while(T--) {
        ll N;
        cin >> N;
        if(__builtin_popcountll(N) == 1) {
            cout << -1 << endl;
        }else {
            vector<int> b;
            for(int i = 0; i < 30; i++) {
                if((N >> i) & 1) b.push_back(i);
            }
            cout << (1 << b[1]) - (1 << b[0]) << endl;
        }
    }
}