#include <bits/stdc++.h>
using namespace std;
using ll=long long;
int main(){
	int ttt;
	cin>>ttt;
	while(ttt--){
		int n;
		cin>>n;
		int ans=0;
		if(__builtin_popcount(n)==1){
			cout<<-1<<endl;
			continue;
		}

		for(int i=0;i<30;i++){
			if(ans==0&&(n>>i&1)==0)continue;
			ans+=(1<<i);
			if(__builtin_popcount(ans+n)<__builtin_popcount(n)){
				break;
			}
		}
		assert(__builtin_popcount(ans+n)<__builtin_popcount(n));
		cout<<ans<<endl;
	}
}