Instructions: You are given a math word problem and you are supposed to only use subtraction on the numbers embedded in the text to answer the following question and then only report the final numerical answer.
Input: Context: Paul had 51 books and 106 pens. After selling some books and pens in a garage sale he had 82 books and 14 pens left.

Question: How many pens did he sell in the garage sale?
Output:
92