Given a math word problem, answer the following question. You might need to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the question and then only report the final numerical answer.

Example Input: there are 28 students in mrs. riley 's class but she only has 19 pencils . how many more pencils does mrs. riley need ?
Example Output: 9

Example Input: sandy had 26 pet fish . she bought 6 more fish . how many pet fish does sandy have now ?
Example Output: 32

Example Input: mrs. hilt 's favorite first grade classes are baking muffins . mrs. brier 's class bakes 18 muffins mrs. macadams 's class bakes 20 muffins and mrs. flannery 's class bakes 17 muffins . how many muffins does first grade bake in all ?
Example Output:
55