/*
*/

#include <bits/stdc++.h>
using namespace std;
#define ALL(x) (x).begin(),(x).end()
#define REP(i, n) for(ll i=0; i<(ll)(n); i++)

template<typename T> int LB(const vector<T>& v, T x) { return lower_bound(ALL(v),x)-v.begin(); }
template<typename T> int UQ(T& v) { sort(ALL(v)); v.erase(unique(ALL(v)),v.end()); return v.size(); }
template<typename T> bool chmax(T &a, T b) { return a<b ? a=b, true : false; }
template<typename T> bool chmin(T &a, T b) { return a>b ? a=b, true : false; }
template<typename T> using rpriority_queue = priority_queue<T,vector<T>,greater<T>>;
using ll=long long; const int INF=1e9+10; const ll INFL=4e18;
using ld=long double; using lll=__int128_t; using ull=unsigned long long;
using VI=vector<int>; using VVI=vector<VI>; using VL=vector<ll>; using VVL=vector<VL>;
using PL=pair<ll,ll>; using VP=vector<PL>; using WG=vector<vector<pair<int,ll>>>;


#ifdef LOCAL
#include "./debug.hpp"
#else
#define debug(...)
#define print_line
#endif


//----------------------------------------------------------

map<string,ll> mp;
int mx=1e5;

void init() {
    for(ll i=1; i<=mx; i++) {
        ll n=i*i;
        string s=to_string(n);
        sort(ALL(s));
        while(s.size()<=10) {
            if(!mp.count(s)) mp[s]=n;
            s="0"+s;
        }
    }
}

void solve() {
    string S; cin>>S;
    sort(ALL(S));

    if(mp.count(S)) cout<<mp[S]<<'\n';
    else cout<<-1<<'\n';
}

int main() {
    init();
    ios::sync_with_stdio(false); cin.tie(nullptr);
    //cout<<fixed<<setprecision(15);
    int T=1;
    cin>>T;
    while(T--) solve();
}