Given an initially empty BST perform the following sequence of operations on the BST leaves. Each positive value indicates a leaf insertion and each negative value a node extraction 10 17 14 21 13 Indicate the structure of the final BST reporting all nodes' key from top to bottom (from root to leaves) and from len tonight (for each tree level). Please report nodes' key as a sequence of integer values separated by a single space. No other symbols must be included in the response. This is an example of the response format: 23 4 5 3 etc