You can only have between zero and 15 cards in your Side Deck.
There are 52 cards in a deck of cards.
There are 108 cards.
There are 39 such cards.
There are 20 such cards.
two cards
32
52
Half the deck of cards are red.
324 cards and that includes 4 category cards.
In a standard deck of playing cards, there are 26 red cards.
52
12