AnrdeyAndBilliard

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

namespace _07.AndreyAndBilliard
{
    public class StartUp
    {
        public static void Main()
        {
            Dictionary<string, decimal> shop = new Dictionary<string, decimal>();
            List<Customer> customers = new List<Customer>();
            int numberOfProducts = int.Parse(Console.ReadLine());

            for (int i = 0; i < numberOfProducts; i++)
            {
                string input = Console.ReadLine();
                var productAndPrice = input
                    .Split(new char[] { '-' }, StringSplitOptions.RemoveEmptyEntries)
                    .ToArray();
                string product = productAndPrice[0];
                decimal price = decimal.Parse(productAndPrice[1]);

                if (!shop.ContainsKey(product))
                {
                    shop.Add(product, price);
                }
                else
                {
                    shop[product] = price;
                }
            }
            while (true)
            {
                string orders = Console.ReadLine();

                if (orders == "end of clients")
                {
                    break;
                }

                var clientOrders = orders
                    .Split(new char[] { ',', '-' }, StringSplitOptions.RemoveEmptyEntries)
                    .ToArray();
                string clientName = clientOrders[0];
                string clientsProduct = clientOrders[clientOrders.Length - 2];
                int productQuantity = int.Parse(clientOrders[clientOrders.Length - 1]);
                if (shop.ContainsKey(clientsProduct))
                {
                    Customer customer = new Customer();
                    customer.Name = clientName;
                    customer.ShopList.Add(clientsProduct, productQuantity);
                    customer.Bill = shop[clientsProduct] * productQuantity;
                    if (customers.Any(x => x.Name == clientName))
                    {
                        var currentCustomer = customers.First(x => x.Name == clientName);

                        if (currentCustomer.ShopList.ContainsKey(clientsProduct))
                        {
                            currentCustomer.ShopList[clientsProduct] += productQuantity;
                            currentCustomer.Bill += shop[clientsProduct] * productQuantity;
                        }
                        else
                        {
                            currentCustomer.ShopList.Add(clientsProduct, productQuantity);
                            currentCustomer.Bill += shop[clientsProduct] * productQuantity;
                        }
                    }
                    else
                    {
                        customers.Add(customer);
                    }
                }
            }
            PrintResult(customers);
        }

        private static void PrintResult(List<Customer> customers)
        {
            decimal totalBill = 0.0m;
                foreach (Customer customer in customers.OrderBy(x => x.Name))
                {
                    Console.WriteLine(customer.Name);
                    foreach (KeyValuePair<string, int> item in customer.ShopList)
                    {
                        Console.WriteLine($"-- {item.Key} - {item.Value}");
                    }
                    Console.WriteLine($"Bill: {customer.Bill:F2}");
                    totalBill += customer.Bill;
                }
                Console.WriteLine($"Total bill: {totalBill:F2}");
        }

        class Customer
        {
            public string Name { get; set; }
            public Dictionary<string, int> ShopList { get; set; }
            public Customer()
            {
                ShopList = new Dictionary<string, int>();
            }
            public decimal Bill { get; set; }
        }
    }
}