We are a small store selling only the finest goods. Unfortunately, our goods are constantly degrading in quality as they approach their sellIn date.

We have a system in place that updates our inventory for us.

Your task is to add a new feature to our system so that we can begin selling a new category of items.

• All items have a sellIn value which denotes the number of days we have left to sell the item. This value decreases by 1 every time update() is called.
• All items have a quality that decreases by 1 whenever update() is called.

Pretty simple, right? Well, this is where it gets interesting:

• The quality of an item is never negative.
• The quality of an item is never more than 50.
• Once the sellIn time has reached zero, quality degrades twice as fast every day.
• "Diamond" has no sellIn time and has a quality that does not change.
• "Vintage Wine" increases in quality the older it gets, at the same rate as regular items.
• "Concert Tickets" increase in quality as its sellIn value decreases.
  • Its quality increases by 1 every day when the sellIn > 10.
  • Its quality increases by 2 every day when the sellIn <= 10 && sellIn > 5.
  • Its quality increases by 3 every day when the sellIn <= 5.
  • Its quality drops to 0 after the concert.

Update our system to include "Chocolate Cake". This item degrades in quality twice as fast as normal items (-2, -4 if sellIn <= 0).