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.

Input: Consider Input: 13 ducks are swimming in a lake . 20 more ducks come to join them . How many ducks are swimming in the lake ?

Output: 33

Input: Consider Input: Joan joined her school 's band . She bought a trumpet for $ 149.16 , a music tool for $ 9.98 , and a song book which was $ 4.14 . Joan found $ 8.65 in her pocket . How much did Joan spend at the music store ?

Output: 163.28

Input: Consider Input: Molly owns the Wafting Pie Company . This morning , her employees used 816 eggs to bake pumpkin pies . If her employees used a total of 1339 eggs today , how many eggs did they use in the afternoon ?
Output: 523