Diabli wiedzą *3,5 Mystery Cache

using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static readonly List<string> Words = new()
    {
        "switch",
        "for",
        "namespace",
        "if",
        "sealed",
        "delegate",
        "enum",
        "checked",
        "default",
        "event",
        "unsafe"
    };

    static IEnumerable<string> Source()
    {
        foreach (var w in Words.Where(w => w.Contains('e') || w.Length <= 3 || w.EndsWith("lt")))
            yield return w;
    }

    static bool HasExactlyTwoVowels(string word)
    {
        return word.Aggregate(
            0,
            (acc, c) => "aeiou".IndexOf(c) >= 0 ? acc + 1 : acc
        ) == 2;
    }

    static string Resolve(Func<IEnumerable<string>, string> rule)
    {
        return rule(Source().Concat(Words).Distinct());
    }

    static int Decode()
    {
        var picks = new[]
        {
            Resolve(seq => seq.First(w => w.Skip(1).Any() && w[^2..] == "lt")),
            Resolve(seq => seq.First(HasExactlyTwoVowels)),
            Resolve(seq => seq.OrderBy(w => w).First(w => w.Length == (1 << 1)))
        };

        return int.Parse(string.Join(
            "",
            picks.Select(w => w.Length.ToString())
        ));
    }

    static Func<int> MainBox()
    {
        int Wrapper() => Decode();
        return Wrapper;
    }

    static void Main()
    {
        var box = MainBox();
        Console.WriteLine("Co jest w pudełku?");
    }
}

N 49° 55.(X - 349)′

E 18° 35.(X - 250)′

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