#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000005
#define Inf64 1000000000000000001LL

int main(){
	
	int _t;
	cin>>_t;
	rep(_,_t){
		long long n;
		cin>>n;
		vector<int> pos;
		rep(i,30){
			if((n>>i)&1)pos.push_back(i);
		}
		if(pos.size()<=1){
			cout<<-1<<endl;
			continue;
		}
		int t = pos[1];
		long long ans = 1LL << (t+1);
		ans -= ((1LL<<(t+1))-1)&n;
		cout<<ans<<endl;
	}
	
}