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

Input: Consider Input: there are 12 birds on the fence . 8 more birds land on the fence . how many birds are on the fence ?

Output: 20

Input: Consider Input: alyssa has 30 books in her library . she bought several books at a yard sale over the weekend . she now has 88 books in her library . how many books did she buy at the yard sale ?

Output: 58

Input: Consider Input: rob is very fond of tall structures . he likes collecting pictures and comparing them . 2 of his favorite buildings are chicago 's sears tower and dubai 's burj khalifa . if burj khalifa stands at 830 meters high and sears stands at 527 meters high how much higher is burj khalifa than sears ?
Output: 303