You are given a node that is the beginning of a linked list. This list contains a dangling piece and a loop. Your objective is to determine the length of the loop.
For example in the following picture the size of the dangling piece is 3 and the loop size is 12:
// Use the `getNext()` method to get the following node.
node.getNext()
Notes:
- do NOT mutate the nodes!
- in some cases there may be only a loop, with no dangling piece