Sum of leaves

Given an array of integers. Create a Binary Search Tree from these numbers. If the number is already in the tree, do not insert it (no duplicates).

Find the sum of all leaves in a tree.

Input

The first line contains number $n(1\le n\le 1000)$. The second line contains $n$ integers.

Output

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

Examples

The sum of leaves equals to $1+5+11=17$.