#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<long long> VL;
typedef vector<VL> VVL;
typedef long long LL;
#define all(a) (a).begin(), (a).end()
#define Yes(n) cout << ((n) ? "Yes" : "No"  ) << endl
#define ALL(a)  (a).begin(),(a).end()
#define pb push_back

LL f(LL n){
  LL m=sqrt(n*1.0);
  m-=10;
  m=max(m,LL(0));
  while(1){
    if(m*m>n){m--;break;}
    m++;
  }
  //cout<<n<<' '<<m<<endl;
  return m;
}

void sol(){
  LL n;cin>>n;
  if(n<=5000){
    rep(i,max(2*n,LL(1000))){
      int j=f(i);
      if(LL(i^j)==n){cout<<i<<endl;return;}
    }
    cout<<-1<<endl;
    return;
  }
  LL m=f(n)-5000;
  m=max(m,LL(0));
  //cout<<'!'<<m<<endl;
  rep(kai,10000){
    LL i=(m^n);
    if(f(i)==m){
      cout<<i<<endl; return ;
    }
    m++;
  }
  cout<<-1<<endl;
}

int main() {
    int t;cin>>t;
    rep(i,t){sol();}
}