GroceryShop83/100

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace GroceryShop
{
    class Program
    {
        static void Main(string[] args)
        {
            string input = Console.ReadLine();
            Regex pattern = new Regex(@"\b(?<![a-z]|[0-9])(?<product>[A-Z][a-z]+)[:](?<price>[0-9]+[.][0-9]{2})\b");

            var result = new Dictionary<string, double>();
            while (input != "bill")
            {
                if (pattern.IsMatch(input))
                {
                    Match m = pattern.Match(input);
                    string product = m.Groups["product"].Value;
                    double price = double.Parse(m.Groups["price"].Value);

                    if (!result.ContainsKey(product))
                    {
                        result.Add(product, price);
                    }
                    else
                    {
                        result[product] = price;
                    }
                }

                input = Console.ReadLine();
            }
            var ordered = result.OrderByDescending(p => p.Value);
            foreach (var item in ordered)
            {
                Console.WriteLine($"{item.Key} costs {item.Value:f2}");
            }

        }
    }
}