/**

 * Definition for binary tree

 * public class TreeNode {

 *     int val;

 *     TreeNode left;

 *     TreeNode right;

 *     TreeNode(int x) { val = x; }

 * }

 */

public class Solution {

    private int maxSum=Integer.MIN_VALUE;

    public int maxPathSum(TreeNode root) {

        if(root==null) return 0;

           max(root);

           return maxSum;

}

     public int max(TreeNode root)

     {  if(root==null) return 0;

        int left=max(root.left);

        int right=max(root.right);

        int maxtemp=root.val;

        if(left>0) maxtemp+=left;

        if(right>0) maxtemp+=right;

        if(maxtemp>maxSum) maxSum=maxtemp;

        return Math.max(0,Math.max(left,right))+root.val;

     }

}