CF1255A.Changing Volume

Bob watches TV every day. He always sets the volume of his TV to $b$. However, today he is angry to find out someone has changed the volume to $a$. Of course, Bob has a remote control that can change the volume.

There are six buttons ($-5, -2, -1, +1, +2, +5$) on the control, which in one press can either increase or decrease the current volume by $1$, $2$, or $5$. The volume can be arbitrarily large, but can never be negative. In other words, Bob cannot press the button if it causes the volume to be lower than $0$.

As Bob is so angry, he wants to change the volume to $b$ using as few button presses as possible. However, he forgets how to do such simple calculations, so he asks you for help. Write a program that given $a$ and $b$, finds the minimum number of presses to change the TV volume from $a$ to $b$.

鲍勃每天都看电视。他总是将电视音量设置为 $b$。然而今天，他生气地发现有人把音量改成了 $a$。当然，鲍勃有一个遥控器，可以调节音量。

遥控器上有六个按钮（$-5, -2, -1, +1, +2, +5$），每次按下其中一个按钮，可使当前音量增加或减少 $1$、$2$ 或 $5$。音量可以任意大，但不能为负数。换言之，若按下某个按钮会导致音量低于 $0$，则该按钮不可按。

由于鲍勃非常生气，他希望用最少的按键次数将音量从 $a$ 调整为 $b$。但他忘记了如何做这样简单的计算，于是向你求助。请编写一个程序：给定 $a$ 和 $b$，求出将电视音量从 $a$ 变为 $b$ 所需的最少按键次数。

Each test contains multiple test cases. The first line contains the number of test cases $T$ ($1 \le T \le 1\,000$). Then the descriptions of the test cases follow.

Each test case consists of one line containing two integers $a$ and $b$ ($0 \le a, b \le 10^{9}$) — the current volume and Bob's desired volume, respectively.

每个测试包含多个测试用例。第一行包含测试用例的数量 $T$（$1 \le T \le 1\,000$）。随后是各测试用例的描述。

每个测试用例由一行组成，包含两个整数 $a$ 和 $b$（$0 \le a, b \le 10^{9}$），分别表示当前音量和 Bob 所期望的音量。

For each test case, output a single integer — the minimum number of presses to change the TV volume from $a$ to $b$. If Bob does not need to change the volume (i.e. $a=b$), then print $0$.

对于每个测试用例，输出一个整数——将电视音量从 $a$ 调整为 $b$ 所需的最少按键次数。如果鲍勃无需调整音量（即 $a = b$），则输出 $0$。

In the first example, Bob can press the $-2$ button twice to reach $0$. Note that Bob can not press $-5$ when the volume is $4$ since it will make the volume negative.

In the second example, one of the optimal ways for Bob is to press the $+5$ twice, then press $-1$ once.

In the last example, Bob can press the $+5$ once, then press $+1$.

在第一个例子中，Bob 可以按两次 $-2$ 按钮到达 $0$。注意：当音量为 $4$ 时，Bob 不能按 $-5$，因为这会使音量变为负数。

在第二个例子中，Bob 的一种最优方案是：先按两次 $+5$，再按一次 $-1$。

在最后一个例子中，Bob 可以先按一次 $+5$，再按一次 $+1$。