You are given an array/list ARR consisting of N integers. Your task is to find the maximum possible sum of a non-empty subarray(contagious) of this array.
Note: An array C is a subarray of array D if it can be obtained by deletion of several elements(possibly zero) from the beginning and the end of array D.

You have been given a Binary Tree of distinct integers and two nodes ‘X’ and ‘Y’. You are supposed to return the LCA (Lowest Common Ancestor) of ‘X’ and ‘Y’.
The LCA of ‘X’ and ‘Y’ in the binary tree is the shared ancestor of ‘X’ and ‘Y’ that is located farthest from the root.
Note :
You may assume that given ‘X’ and ‘Y’ definitely exist in the given binary tree.