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

using i32 = int;
using i64 = long long;
using u64 = unsigned long long;
using i128 = __int128_t;
using f64 = long double;
using p2 = pair<i64, i64>;
using el = tuple<i64, i64, i64>;
using mint = atcoder::modint998244353;

void _main();
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  _main();
}

i64 pow(i64 x, i64 n, i64 m) {
  i64 res = 1;
  i64 t = x % m;
  while (n > 0) {
    if (n & 1) {
      res = res * t % m;
    }
    t = t * t % m;
    n >>= 1;
  }
  return res;
}

void _main() {
  i64 ttt;
  cin >> ttt;
  map<vector<i64>, i64> mp;
  for (i64 i = 1; i * i <= 10000000000; i++) {
    i64 x = i * i;
    vector<i64> v;
    while (x > 0) {
      v.push_back(x % 10);
      x /= 10;
    }
    sort(v.begin(), v.end());
    if (!mp.count(v)) mp[v] = 1e18;
    mp[v] = min(mp[v], i * i);
  }
  while (ttt--) {
    i64 n;
    cin >> n;
    vector<i64> v;
    while (n > 0) {
      v.push_back(n % 10);
      n /= 10;
    }
    i64 ans = 1e18;
    sort(v.begin(), v.end());
    if (mp.count(v)) ans = mp[v];
    reverse(v.begin(), v.end());
    while (!v.empty() && v.back() == 0) {
      v.pop_back();
      vector<i64> nv = v;
      reverse(nv.begin(), nv.end());
      if (mp.count(nv)) ans = min(ans, mp[nv]);
    }
    cout << (ans == 1e18 ? -1 : ans) << "\n";
  }
}