Little Petya likes to play very much. And most of all he likes to play the following game:

He is given a sequence of N integer numbers. At each step it is allowed to increase the value of any number by 1 or to decrease it by 1. The goal of the game is to make the sequence non-decreasing with the smallest number of steps. Petya is not good at math, so he asks for your help.

The sequence a is called non-decreasing if a1 \le a2 \le ... \le aN holds, where N is the length of the sequence.

The first line of the input contains single integer N (1 \le N \le 5000) - the length of the initial sequence. The following N lines contain one integer each - elements of the sequence. These numbers do not exceed 109 by absolute value.

Output one integer - minimum number of steps required to achieve the goal.