using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        Dictionary<int, decimal> prices = new Dictionary<int, decimal>();

​

        int count = 0;

        bool finished = false;

        do

        {

            Console.Write("Item {0}:\tEnter Price: $", count);

​

            var price = Console.ReadLine();

            var convertedPrice = Convert.ToDecimal(price);

            if(convertedPrice != -1)

            {

                prices.Add(count, convertedPrice);

                count++;

            }

            else

            {

                finished = true;

            }

        } while(!finished);

        Console.WriteLine("Price History");

        foreach(var price in prices)

        {

            Console.WriteLine("Item {0}:\tPrice: ${1}", price.Key, price.Value);

        }

    }

}