Sum of numbers in a tree

Given an array of integers. Create a Binary Search Tree from these numbers. If the inserted value equals to the current node, insert it to the right subtree.

Write method Sum that returns the sum of numbers in all nodes of a tree.

Write the code according to the next interface:

class TreeNode
{
public:
    int val;
    TreeNode *left, *right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};

class Tree 
{
public:
    TreeNode *head;
    Tree() : head(NULL) {};
    void Insert(int val); // Insert number val to Binary Search Tree
    int Sum(void); // Return the sum of numbers in all nodes of a tree
};

You can create (use) additional methods if needed.

Input

The first line contains number n (1 ≤ n ≤ 100). The second line contains n integers.

Output

Create the Binary Search Tree from input data. Print the sum of numbers in all nodes of a tree.

Examples