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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    constexpr int r = 32000;
    vector<pair<ll,int>> a(r + 1);
    array<int, 10> cnt{};
    for(int i = 1; i <= r; i++){
        cnt.fill(0);
        int v = i * i;
        while(v){
            int d = v / 10;
            cnt[v - d * 10]++;
            v = d;
        }
        for(int j = 9; j >= 0; j--) a[i].first = a[i].first * 10 + cnt[j];
        a[i].second = i * i;
    }
    sort(a.begin(), a.end());
    int T, v;
    cin >> T;
    while(T--){
        cin >> v;
        ll hs = 0;
        cnt.fill(0);
        while(v){
            int d = v / 10;
            cnt[v - d * 10]++;
            v = d;
        }
        for(int i = 9; i >= 0; i--) hs = hs * 10 + cnt[i];
        int ans = 1 << 30;
        while(1){
            if(hs == 0) break;
            int p = lower_bound(a.begin(), a.end(), make_pair(hs, -1)) - a.begin();
            if(p < a.size() && a[p].first == hs){
                 ans = min(ans, a[p].second);
            }
            if(hs % 10 == 0) break;
            hs--;
        }
        if(ans >> 30) ans = -1;
        cout << ans << '\n';
    }
}