#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define all(x) (x).begin(), (x).end()
using ll = long long;
const ll MOD = 998244353;
#include<atcoder/all>
using namespace atcoder;
using mint = modint998244353;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  ll t;cin>>t;
  map<vector<ll>,ll> mp;
  ll cnt=1;
  while(cnt*cnt<=1e9+1){
    ll cnt2=cnt*cnt;
    string s=to_string(cnt2);
    vector<ll> tmp(10,0);
    for(auto c:s) tmp[c-'0']++;
    if(!mp.count(tmp)) mp[tmp]=cnt2;
    cnt++;
  }
  while(t--){
    string n;cin>>n;
    vector<ll> tmp(10,0);
    for(auto c:n) tmp[c-'0']++;
    ll ans=LLONG_MAX;
    ll q=tmp[0];
    rep(i,q+1){
        if(mp.count(tmp)){
            ans=min(ans,mp[tmp]);
        }
        tmp[0]--;
    }
    if(ans==LLONG_MAX) cout<<-1<<"\n";
    else cout<<ans<<"\n";
  }
}