#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;
#define rep(i, s, t) for (ll i = s; i < (ll)(t); i++)
#define all(x) begin(x), end(x)

template <class T> bool chmin(T& x, T y) {
	return x > y ? (x = y, true) : false;
}
template <class T> bool chmax(T& x, T y) {
	return x < y ? (x = y, true) : false;
}

struct io_setup {
	io_setup() {
		ios::sync_with_stdio(false);
		std::cin.tie(nullptr);
		cout << fixed << setprecision(15);
	}
} io_setup;

vector<int> cnt_string(int x) {
	vector<int> res(10);
	while (x > 0) {
		res[x % 10]++;
		x /= 10;
	}
	return res;
}

map<vector<int>, int> mp;

void solve() {
	int x;
	cin >> x;
	auto v = cnt_string(x);
	int ans = 2e9;
	while (v[0] >= 0) {
		if (mp.count(v)) chmin(ans, mp[v]);
		v[0]--;
	}
	if (ans == 2e9) ans = -1;
	cout << ans << "\n";
}

int main() {
	rep(i, 1, 4e4) {
		auto ri = cnt_string(i * i);
		if (!mp.count(ri)) mp[ri] = i * i;
	}
	int t = 1;
	cin >> t;
	while (t--) solve();
}