You are given an array $A$ of $N$ integers. Your task is to print the sum of numbers that occurs for an even number of times in the array.

Input format

• First line: A single integer $N$
• Second line: $N$ space-separated integers denoting array $A$

Output format

Print a single integer denoting the sum of numbers that appeared for even times in the array.

Constraints

$1 \le N \le 10^5\\ 1 \le A_i \le 10^9$

Edited problem statement

You are given an array $A$ of $N$ integers. Your task is to print the sum of numbers that is occurring for an even number of times in the array.

Input format

• The first line of the input contains a single integer $N$ denoting the number of integers or elements in the array.
• The second line of the input contains $N$ space-separated integers denoting the elements of array $A$.

Output format

Print a single integer denoting the sum of numbers that appeared for the even number of times in the array.

Constraints

$1 \le N \le 10^5\\ 1 \le A_i \le 10^9$