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

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

\(1 \le N \le 10^5\\ 1 \le A_i \le 10^9\)