描述

Background
Mr Somurolov, fabulous chess-gamer indeed, asserts that no one else but him can move knights from one position to another so fast. Can you beat him?
The Problem
Your task is to write a program to calculate the minimum number of moves needed for a knight to reach one point from another, so that you have the chance to be faster than Somurolov.
For people not familiar with chess, the possible knight moves are shown in Figure 1.

输入

The input begins with the number n of scenarios on a single line by itself.
Next follow n scenarios. Each scenario consists of three lines containing integer numbers. The first line specifies the length l of a side of the chess board (4 <= l <= 300). The entire board has size l * l. The second and third line contain pair of integers {0, ..., l-1}*{0, ..., l-1} specifying the starting and ending position of the knight on the board. The integers are separated by a single blank. You can assume that the positions are valid positions on the chess board of that scenario.

输出

For each scenario of the input you have to calculate the minimal amount of knight moves which are necessary to move from the starting point to the ending point. If starting point and ending point are equal,distance is zero. The distance must be written on a single line.

翻译

描述

背景
传说中的象棋玩家Somurolov先生断言，除了他，没有人能如此迅速地将骑士从一个位置移动到另一个位置。你能打败他吗?
问题
你的任务是编写一个程序来计算一个骑士从另一个点到达另一个点所需的最小移动数，这样你就有机会比Somurolov更快。
对于不熟悉国际象棋的人，可能的骑士走法如图1所示。

输入

输入以单行中场景的数量n开始。
接下来是n个场景。每个场景由包含整数的三行组成。第一行指定了棋盘边的长度l (4 <= l <= 300)。整块板的大小为l * l，第二和第三行包含一对整数{0，…l - 1} *{0,…， l-1}指定骑士在棋盘上的开始和结束位置。整数之间用一个空格分隔。你可以假设这些位置是棋盘上的有效位置。

输出

对于输入的每个场景，你必须计算出骑士从起点移动到终点所需的最小移动量。如果起点和终点相等，距离为零。距离必须写在一行上。