You are being asked to create a subsystem for a finance organization.
    Given the following rules, create a scala program that will generate the required Accounting Totals (as defined below).

    Calculate the following Accounting Totals.
    1. Gross Sales (total of sales) Account#123456
      This is the sum of all sales for all sites. If a given site has no sales, post a '0' value.
    2. Inventory Value => Account#2983018
      This is the current value of the inventory in all sites. If a given site has no inventory, or is somehow negative, post that.
    3. Inventory Value Change From Yesterday => Account#3485719
      This is the difference between yesterday's and today's inventory value for a given site.
    4. Net Sales (Sales minus incoming inventory) => Account#4928392
      This is the amount of sales, but we