4) Consider calculating the round 16 key in DES. Given that the input key, with odd parity bits, when described in HEX is "A197 47F2 E9C1 B35D", determine the first 10 bits of the round 16 key. (Note: While it looks like an inordinate amount of calculation is necessary here, it turns out that a particular observation that I might off-hand in class makes this calculation very quick. I would strongly not recommend trying to "brute force" this question. Rather, I'd recommend only doing it if you make the observation that allows you to do this question in a minute or so.) Credit will only be given if appropriate work is shown since it's easy to randomly put bits down and get around half of them. I'll decide what appropriate work is!!!