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.

Input: Consider Input: the book fair sold 4 posters . now they have 2 posters left . how many posters did they have to begin with ?

Output: 6

Input: Consider Input: ted and fred measured their height . fred 's height is 98 inches . ted is 39 inches tall . what 's the difference between ted 's height and fred 's height ?

Output: 59

Input: Consider Input: upon arriving at the school buddy immediately went to his teacher where he was introduced to all the third grade students in the school . there were 57 girl students and 66 boy students . how many third graders did buddy meet in the school ?
Output: 123