Janessa has a plan to give her brother Dexter his first collection of baseball cards. She currently has 4 cards in addition to the 13 that her father gave her.  She ordered a collection of 36 cards from eBay. After inspecting the cards she found 4 cards are in bad shape and decides to throw them away. Janessa ended up giving Dexter 29 cards. How many cards did Janessa keep for herself?
Please reason step by step, and put your final answer within \boxed{}.
user