class Inventory {

private:

   String2002 item;
   int stock;
   int minOnHand;
   int numSold;

public:

   // creates a new item in the inventory called "item" with 0 items on hand.
   Inventory(String2002 item);
   
   // creates a new item in the inventory called "item" with number items on hand.
   // Throws invalid_argument if number is less than zero.
   Inventory(String2002 item, int number);

   // reduces the inventory by the amount sold.  
   // If the amount is negative or will cause the number of items on hand to become
   // negative, an invalid_argument is thrown.
   void sell(int amount);

   // stocks up on the item, if required.
   // If the number of items on hand is less than the amount given, 20 more items are
   // added to the inventory.
   // If the amount is negative an invalid_argument is thrown.
   void stockUp(int amount);

   // returns the number of items in the warehouse.
   int getStock() const;

   // returns the name of the item.
   String2002 getItem() const;

   // returns the total number of this item sold to date.
   int totalSold() const;

   // prints the minimum number of this item in the warehouse to date.
   void printMinInventory() const;

};