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.

[EX Q]: Heather weighs 87 pounds . Emily weighs 9 pounds . Elizabeth weighs 8 pounds . How much heavier is Heather than Emily ?
[EX A]: 78

[EX Q]: Paul had saved up 4 dollars . If he received another 11 dollars for his allowance , how many 5 dollar toys could he buy ?
[EX A]: 3

[EX Q]: A treasure hunter discovered a buried treasure chest filled with a total of 5155 gems . 45 of the gems were diamonds , and the rest were rubies . How many of the gems were rubies ?
[EX A]:
5110