CF351E.Jeff and Permutation

Jeff's friends know full well that the boy likes to get sequences and arrays for his birthday. Thus, Jeff got sequence _p_1, _p_2, ..., p__n for his birthday.

Jeff hates inversions in sequences. An inversion in sequence _a_1, _a_2, ..., a__n is a pair of indexes i, j (1 ≤ i < j ≤ n), such that an inequality a__i > a__j holds.

Jeff can multiply some numbers of the sequence p by -1. At that, he wants the number of inversions in the sequence to be minimum. Help Jeff and find the minimum number of inversions he manages to get.

杰夫的朋友们非常清楚，这个男孩喜欢在生日时收到序列和数组。因此，杰夫生日收到了序列 $p_1,\ p_2,\ \dots,\ p_n$。

杰夫讨厌序列中的逆序对。在序列 $a_1,\ a_2,\ \dots,\ a_n$ 中，一个逆序对是指一对下标 $(i,\ j)$（满足 $1 \le i < j \le n$），使得不等式 $a_i > a_j$ 成立。

杰夫可以将序列 $p$ 中的某些数乘以 $-1$。他希望经过操作后，序列中的逆序对数量尽可能少。请帮助杰夫，求出他所能达到的最小逆序对数量。

The first line contains integer n (1 ≤ n ≤ 2000). The next line contains n integers — sequence _p_1, _p_2, ..., p__n (|p__i| ≤ 105). The numbers are separated by spaces.

第一行包含一个整数 $n$（$1 \leq n \leq 2000$）。下一行包含 $n$ 个整数——序列 $p_1, p_2, \dots, p_n$（$|p_i| \leq 10^5$）。数字之间用空格分隔。

In a single line print the answer to the problem — the minimum number of inversions Jeff can get.

在一行中输出问题的答案——Jeff 能得到的最少逆序对数量。