using System;
using System.Globalization;

internal static class Program
{
    private static void Main(string[] args)
    {
        BookingRecord? record = ParseRecord("W-17|3");
        if (record is null) throw new InvalidOperationException("Fixture rejected");
        Console.WriteLine($"{record.Code}: {record.Places}");
        Console.WriteLine($"Junk accepted: {ParseRecord("W-17|3x") is not null}");
    }

    internal static BookingRecord? ParseRecord(string? line)
    {
        if (line is null) return null;
        string[] fields = line.Split('|');
        if (fields.Length != 2 || string.IsNullOrWhiteSpace(fields[0])) return null;
        foreach (char c in fields[0]) if (char.IsWhiteSpace(c)) return null;
        if (!int.TryParse(fields[1], NumberStyles.None, CultureInfo.InvariantCulture, out int places) || places is < 1 or > 20) return null;
        return new BookingRecord(fields[0], places);
    }
}

internal sealed record BookingRecord(string Code, int Places);