What is the sum of all the two digit primes that are greater than 12 but less than 99 and are still prime when their two digits are interchanged?

Oh, dude, you want me to do math now? Fine, fine. So, the two-digit primes that are greater than 12 but less than 99 and still prime when you swap their digits are 13, 17, 31, 37, 71, 73, 79, and 97. Add them up and you get 398. Math is fun, right?