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 ≤ a2 ≤ ... ≤ aN holds, where N is the length of the sequence. The first line of the input contains single integer N (1 ≤ N ≤ 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.