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.
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Question: mrs. sheridan has 17 cats . mr. sheridan gave her 14 more cats . how many cats does mrs. sheridan have altogether ?

Answer: 31

Question: zachary did 47 push-ups in gym class today . david did 15 more push-ups than zachary . how many push-ups did david do ?

Answer: 62

Question: mother bought some potatoes . she used 15 of the potatoes to make salads and 24 of the potatoes for mashed potatoes . if there were 13 potatoes left how many potatoes did mother buy at first ?

Answer:
52