Two people, Alice and Bob are using the key sharing algorithm. They have chosen a clock size of 17 and a base of 5. Alice's private number is 4, while Bob's is 6. The first step in creating the shared key is for each party to generate a PPN based on their private number, the base and the clock size. Alice has already sent her PPN to Bob. She receives Bob's PPN, which is 2. Alice uses Bob's PPN (2), her private number (4), and the clock size (17) to calculate the shared key. What is it