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.

Example Input: Ned was helping the cafeteria workers pick up lunch trays , but he could only carry 5 trays at a time . If he had to pick up 5 trays from one table and 5 trays from another , how many trips will he make ?
Example Output: 2

Example Input: Heather weighs 87 pounds . Emily weighs 9 pounds . Elizabeth weighs 8 pounds . How much heavier is Heather than Emily ?
Example Output: 78

Example Input: Ronald has 13 blocks . Martha has with 4 blocks . Martha finds another 80 . How many blocks does Martha end with ?
Example Output:
84