#include 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)*2; for(long long i=N-sN-ssN; i<=N-sN+ssN; i++){ if(i < 0) continue; if((Sqrt(i)^i) == N){answer = i; break;} } if(answer == -1) for(long long i=N+sN-ssN; i<=N+sN+ssN; i++){ if(i < 0) continue; if((Sqrt(i)^i) == N){answer = i; break;} } cout << answer << "\n"; } }