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: john threw a halloween party where 13 people showed up . if only 6 dressed up how many people did n't wear costumes ?

Output: 7

Input: Consider Input: a farmer had 46 tomatoes from his garden . after picking some he had 3 left . how many did he pick ?

Output: 43

Input: Consider Input: a group of 4 friends were playing video games . later 3 more friends came over . how many people were there total ?
Output: 7