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

#define rep(i, l, r) for (int i = (int)(l); i<(int)(r); i++)
#define ll long long
#define all(x) (x).begin(), (x).end()
#define siz(x) (int)(x).size()

const int inf = 1e9;
const ll INF = 4e18;

template<class T>bool chmax(T &a, T b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, T b) { if (b<a) { a=b; return 1; } return 0; }

vector<int> di = {-1, 0, 1, 0}, dj = {0, -1, 0, 1};

void solve() {
    int T; cin >> T;
    map<array<int, 10>, ll> mp;
    for (ll x = 1; x * x <= 1e10; x++) {
        ll t = x * x;
        string s = to_string(t);
        array<int, 10> cnt;
        rep(i, 0, 10) cnt[i] = 0;
        for (char c : s) {
            cnt[c-'0']++;
        }
        if (!mp.contains(cnt)) {
            mp[cnt] = x * x;
        }
    }
    // cout << "ok" << endl;
    while(T--) {
        string N; cin >> N;
        array<int, 10> cnt;
        rep(i, 0, 10) cnt[i] = 0;
        for (char c : N) {
            cnt[c-'0']++;
        }
        // rep(i, 0, 10) cout << cnt[i] << " ";
        // cout << endl;
        //0の個数を全探索
        ll ans = INF;
        rep(x, 0, 11) {
            if (mp.contains(cnt)) {
                chmin(ans, mp[cnt]);
            }
            cnt[0]--;
        }
        if (ans == INF) ans = -1;
        cout << ans << endl;
    }
}

int main() {
#ifndef ONLINE_JUDGE
    freopen("in.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
#endif
    int T = 1; 
    // cin >> T;
    while(T--) {
        solve();
    }
}