F. Buy One, Get One Free
time limit per test
5 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

A nearby pie shop is having a special sale. For each pie you pay full price for, you may select one pie of a strictly lesser value to get for free. Given the prices of all the pies you wish to acquire, determine the minimum total amount you must pay for all of the pies.

Input

Input will begin with an integer n (1 ≤ n ≤ 500000), the number of pies you wish to acquire. Following this is a line with n integers, each indicating the cost of a pie. All costs are positive integers not exceeding 109.

Output

Print the minimum cost to acquire all the pies.

Please, do not use the %lld specifier to read or write 64-bit integers in С++. It is preferred to use the cin, cout streams or the %I64d specifier.

Examples
Input
63 4 5 3 4 5
Output
14
Input
55 5 5 5 5
Output
25
Input
4309999 6000 2080 2080
Output
314159
Note

In the first test case you can pay for a pie with cost 5 and get a pie with cost 4 for free, then pay for a pie with cost 5 and get a pie with cost 3 for free, then pay for a pie with cost 4 and get a pie with cost 3 for free.

In the second test case you have to pay full price for every pie.