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

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

    auto Sqrt = [&](long long x) -> long long {
        if(x == 0) return 0;
        if(x <= 3) return 1;
        long long s = sqrt(x);

        if(s*s == x) return s;
        if((s-1)*(s-1) == x) return s-1;
        if((s+1)*(s+1) == x) return s+1;
        
        if(s*s >= x) return s-1;
        if((s+1)*(s+1) >= x) return s;
        return s+1;
    };

    int T; cin >> T;
    while(T--){
        long long N; cin >> N;
        long long answer = -1;
        for(int i=0; i<=100; i++) if((Sqrt(i)^i) == N){answer = i; break;}
        if(answer != -1){cout << answer << "\n"; continue;}
        
        long long sn = Sqrt(N),ssn = Sqrt(sn)*1.4;
        for(long long s=sn-ssn; s<=sn+ssn; s++){
            if(s < 0) continue;
            long long L = s*s,R = (s+1)*(s+1);
            long long left = N^s;
            if(L <= left && left < R){answer = left; break;}
        }
        cout << answer << "\n";
    }
}