#include <bits/stdc++.h>

#include <atcoder/all>
using namespace std;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
#define FAST_IO                \
  ios::sync_with_stdio(false); \
  cin.tie(0);
const i64 INF = 1001001001001001001;
using Modint = atcoder::static_modint<998244353>;

int main() {
  FAST_IO

  map<string, int> mp;
  for (int i = 0; i * i <= 1e9 + 10; ++i) {
    string s = to_string(i * i);
    sort(s.begin(), s.end());
    if (mp.count(s) == 0 || mp[s] > i * i) {
      mp[s] = i * i;
    }
  }

  int T;
  cin >> T;
  while (T--) {
    string N;
    cin >> N;

    sort(N.begin(), N.end());
    int inf = 1e9 + 10;
    int mn = mp.count(N) ? mp[N] : inf;

    while (N.size() > 0 && N.front() == '0') {
      N.erase(N.begin());
      mn = min(mn, mp.count(N) ? mp[N] : inf);
    }
    if (mn == inf) {
      cout << -1 << endl;
    } else {
      cout << mn << endl;
    }
  }
}