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 4 6 10 13 7 18 20 3 9 16 Report the key of all leaves of the final BST considering them from left to right, Please report all nodes keys 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. Risposta: Successivo Windou