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 map led them through the forest and into a cave . to open the cave doors they need to put weights on the switch . if the switch already has 234 lbs . of weights and the total needed is 712 lbs . how much more weight to they need to add ?

Output: 478

Input: Consider Input: julia played tag with 12 kids on monday . she played tag with 7 kids on tuesday . how many kids did she play with altogether ?

Output: 19

Input: Consider Input: on the day of the awarding ceremony robyn and lucy decided to sell more cookies during the morning to make sure they get the badge . lucy sold 19 packs and robyn sold 16 how many packs did they sell on their last day ?
Output: 35