You are given the root of a binary tree, and your task is to determine the maximum depth of this tree. The maximum depth of a binary tree is determined by the count of nodes found on the longest path from the root node to the farthest leaf node.

Constraints:

• The number of nodes in the tree is in the range $[1, 500].$

• $-100 \leq$Node.data $\leq 100$ ...