using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var dic = new Dictionary<int, int>();
        for (var i = 1; ; ++i)
        {
            var d = i * i;
            if (d > 1_000_000_000) break;
            var s = d.ToString().Select(c => c - '0').ToList();
            s.Sort();
            var p = 0;
            foreach (var c in s) p = p * 10 + c;
            if (!dic.ContainsKey(p)) dic[p] = d;
        }
        var t = NN;
        var ans = new int[t];
        for (var u = 0; u < t; ++u)
        {
            var s = ReadLine().Select(c => c - '0').ToList();
            s.Sort();
            var p = 0;
            foreach (var c in s) p = p * 10 + c;
            if (dic.ContainsKey(p)) ans[u] = dic[p];
            else ans[u] = -1;
        }
        WriteLine(string.Join("\n", ans));
    }
}