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.

[Q]: John weighs 81 pounds . Roy weighs 4 pounds . How much heavier is John than Roy ?
[A]: 77


[Q]: Mary had 7 nickels in her bank . Her dad gave her 5 nickels . How many nickels does Mary have now ?
[A]: 12


[Q]: There are 43 pencils in the drawer and 19 pencils on the desk . Dan placed 16 more pencils on the desk . How many pencils are now there in total ?
[A]:
78