CF11B.Jumping Jack

Jack is working on his jumping skills recently. Currently he's located at point zero of the number line. He would like to get to the point x. In order to train, he has decided that he'll first jump by only one unit, and each subsequent jump will be exactly one longer than the previous one. He can go either left or right with each jump. He wonders how many jumps he needs to reach x.

杰克最近正在练习他的跳跃技能。目前，他位于数轴上的原点（即位置 0）。他希望到达位置 $x$。为了训练，他决定：第一次跳跃的长度为 1 个单位，之后每次跳跃的长度都比前一次恰好长 1 个单位。每次跳跃时，他可以选择向左或向右跳。他想知道：最少需要多少次跳跃才能到达位置 $x$？

The input data consists of only one integer x ( - 109 ≤ x ≤ 109).

输入数据仅包含一个整数 $x$（$-10^9 \leq x \leq 10^9$）。

Output the minimal number of jumps that Jack requires to reach x.

输出 Jack 到达位置 $x$ 所需的最少跳跃次数。