So the question is: suppose that Alice forgets the value that she used
for the initialization vector--she encrypted some file, she has the ciphertext
and she has the key. Can she still recover n, even though she forgot the IV?
--the Initial Value--
So the answers are: "No," she can't recover any of them;
"Almost," that she can recover all of them except for the very first block;
"Almost," that she can recover all of them except for the first and the second block;
or that she can only recover the very last block of n.
