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

class yuki321
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static void Main()
    {
        var t = NN;
        var str = "CCCFACCFAACCCCBACCCBA";
        var list = new List<int>(new[] { 0, 5, 10 });
        var reslist = new List<string>();
        for (var i = 0; i < t; ++i)
        {
            var n = NN;
            if (!list.Contains(n % 21))
            {
                reslist.Add("-1");
                continue;
            }
            var res = string.Concat(Enumerable.Repeat(str, (n + 20) / 21)).Take(n).ToList();
            res.Reverse();
            reslist.Add(string.Concat(res));
        }
        WriteLine(string.Join("\n", reslist));
    }
}