AndreyAndBilliard

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

class Customer
{
    public string Name { get; set; }
    public Dictionary<string, int> ProductQuantity { get; set; }
    public decimal Bill { get; set; }
}

class AndreyAndBilliard
{
    static void Main()
    {
        var entities = new Dictionary<string, decimal>();

        int entitiesCount = int.Parse(Console.ReadLine());

        for (int i = 0; i < entitiesCount; i++)
        {
            var newEntity = Console.ReadLine().Split('-').ToArray();
            string entityName = newEntity[0];
            decimal entityPrise = decimal.Parse(newEntity[1]);

            if (!entities.ContainsKey(entityName))
            {
                entities.Add(entityName, entityPrise);
            }
            else
            {
                entities[entityName] = entityPrise;
            }
        }

        List<Customer> allCustomers = new List<Customer>();

        string command = Console.ReadLine();
        while (command != "end of clients")
        {
            string[] commandArgs = command.Split(new char[] { '-', ',' }, StringSplitOptions.RemoveEmptyEntries);

            if (entities.ContainsKey(commandArgs[1]))
            {
                string product = commandArgs[1];
                int quantity = int.Parse(commandArgs[2]);
                decimal spent = decimal.Parse(commandArgs[2]) * entities[commandArgs[1]];

                Customer currentCustomer = new Customer();
                currentCustomer.Name = commandArgs[0];
                currentCustomer.ProductQuantity = new Dictionary<string, int>();
                currentCustomer.ProductQuantity.Add(product, quantity);
                currentCustomer.Bill = spent;

                allCustomers.Add(currentCustomer);
            }

            command = Console.ReadLine();
        }

        decimal totalBill = 0;
        foreach (var customer in allCustomers.OrderBy(x => x.Name))
        {
            Console.WriteLine(customer.Name);
            foreach (var product in customer.ProductQuantity)
            {
                Console.WriteLine("-- {0} - {1}",
                    product.Key, product.Value);
            }
            Console.WriteLine("Bill: {0:f2}", customer.Bill);
            totalBill += customer.Bill;
        }
        Console.WriteLine("Total bill: {0:f2}", totalBill);
    }
}