You are given a math word problem and you are supposed to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

[EX Q]: Karen has 639 crayons . Cindy has 504 crayons . How many more crayons does Karen have than Cindy ?
[EX A]: 135

[EX Q]: There are 22 orchid bushes and 40 orange trees currently in the park . Park workers will plant 13 orchid bushes today . How many orchid bushes will the park have when the workers are finished ?
[EX A]: 35

[EX Q]: Jovana had 5 pounds of shells in her bucket . She added some shells and now has 28 pounds of shells . How many pounds did she add ?
[EX A]:
23