int maxPathSum(struct Node *root, int &result) {
    if (root == NULL) return 0;  // Base case
    // Find maximum sum in left and right subtree. Also find
    // maximum root to leaf sums in left and right subtrees
    // and store them in lLPSum and rLPSum
    int lcost = maxPathSum(root->left, res);
    int rcost = maxPathSum(root->right, res); //Step 1

    // Find the maximum path sum passing through root
    int curr_sum = lcost + rcost + root->data;

    // Update res (or result) only when needed
    if (result < curr_sum && (root->left && root->right)) {
        result = curr_sum;// step 2
    }


    // Return the maximum (root to leaf path) cost
    if (root->left == NULL) {// step 3
        return root->value + rcost;
    } else if (root->right == NULL) {
        return root->value + lcost;
    }
    return max(lcost, rcost) + root->data;
 }

// The main function which returns sum of the maximum
// sum path between two leaves.  This function mainly uses
// maxPathSum()
 int FindMaxPathCost(Node *root) {
    int result = 0;
    maxPathSum(root, result);
    return result;
 }