Height of Binary Tree

class Node {
    int data;
    Node left, right;

    Node(int item) {
        data = item;
        left = right = null;
    }
}

class Solution {
    // Function to find the height of a binary tree.
    int height(Node node) {
        if (node == null)
            return -1;
        return Math.max(height(node.left), height(node.right)) + 1;
    }
}