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

using ll = long long;
#define rep(i, a, n) for(int i = a; i < n; i++)

int main() {
	int T;
	cin >> T;
	map<string, vector<int>> mp;
	ll n = 1e10;
	for(ll i = 1; i * i < n; i++) {
		int sq = i * i;
		string s = to_string(sq);
		sort(s.begin(), s.end(), greater<char>());
		mp[s].push_back(sq);
	}
	for(auto it = mp.begin(); it != mp.end(); it++) {
		sort(it->second.begin(), it->second.end());
	}
	rep(ti, 0, T) {
		string s;
		cin >> s;
		sort(s.begin(), s.end(), greater<char>());
		ll inf = 1e10;
		ll a = inf, b = inf;
		if(mp.count(s)) a = mp[s][0];
		while(s.back() == '0') s.pop_back();
		if(mp.count(s)) b = mp[s][0];
		if(a != inf || b != inf) cout << min(a, b) << endl;
		else cout << -1 << endl; 
	}

}