You are given a math word problem and you are supposed to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the following question and then only report the final numerical answer.
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Question: Mary had 21 dimes and 38 pennies in her bank . Her dad borrowed 18 pennies from Mary . How many pennies does she have now ?

Answer: 20


Question: For a birthday party George bought 10 regular sodas and 22 diet sodas . If his fridge would only hold 4 on each shelf , how many shelves would he fill up ?

Answer: 8


Question: Lizette has 813 stamps . Lizette has 125 more stamps than Minerva . How many stamps does Minerva have ?

Answer:
688