Sales Report

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

public class Sale
{
    public string Town { get; set; }
    public string Product { get; set; }
    public decimal Price { get; set; }
    public decimal Quantity { get; set; }

    public decimal TotalPrice
    {
        get
        {
            return Price * Quantity;
        }
    }

    public Sale(string town, string product, decimal price, decimal quantity)
    {
        Town = town;
        Product = product;
        Price = price;
        Quantity = quantity;
    }
}

public class Program
{

    public static void Main()
    {
        var sales = ReadSales();

        var townTotalPair = new SortedDictionary<string, decimal>();
        foreach (var sale in sales)
        {
            var town = sale.Town;
            townTotalPair[town] = townTotalPair.ContainsKey(town)
                ? townTotalPair[town] + sale.TotalPrice
                : sale.TotalPrice;
        }

        foreach (var pair in townTotalPair)
            Console.WriteLine($"{pair.Key} -> {pair.Value:f2}");
    }

    private static Sale[] ReadSales()
    {
        var numberOfSales = int.Parse(Console.ReadLine());
        var sales = new Sale[numberOfSales];

        for (int index = 0; index < numberOfSales; index++)
        {
            var saleInfo = Console.ReadLine().Split();
            sales[index] = new Sale(
                town: saleInfo[0],
                product: saleInfo[1],
                price: decimal.Parse(saleInfo[2]),
                quantity: decimal.Parse(saleInfo[3]));
        }

        return sales;
    }
}