CF1816A.Ian Visits Mary

Ian and Mary are frogs living on lattice points of the Cartesian coordinate plane, with Ian living on $(0,0)$ and Mary living on $(a,b)$.

Ian would like to visit Mary by jumping around the Cartesian coordinate plane. Every second, he jumps from his current position $(x_p, y_p)$ to another lattice point $(x_q, y_q)$, such that no lattice point other than $(x_p, y_p)$ and $(x_q, y_q)$ lies on the segment between point $(x_p, y_p)$ and point $(x_q, y_q)$.

As Ian wants to meet Mary as soon as possible, he wants to jump towards point $(a,b)$ using at most $2$ jumps. Unfortunately, Ian is not good at maths. Can you help him?

A lattice point is defined as a point with both the $x$-coordinate and $y$-coordinate being integers.

伊恩和玛丽是生活在笛卡尔坐标平面上格点处的两只青蛙，其中伊恩住在 $(0,0)$，玛丽住在 $(a,b)$。

伊恩希望借助在笛卡尔坐标平面上跳跃的方式去拜访玛丽。每一秒，他从当前位置 $(x_p, y_p)$ 跳到另一个格点 $(x_q, y_q)$，要求线段 $(x_p, y_p)$ 与 $(x_q, y_q)$ 之间（不包括端点）不经过任何其他格点。

由于伊恩希望尽快与玛丽会面，他希望最多通过 $2$ 次跳跃就到达点 $(a,b)$。遗憾的是，伊恩不擅长数学。你能帮他吗？

格点定义为横、纵坐标均为整数的点。

The first line contains a single integer $t$ ($1 \le t \le 500$) — the number of test cases. The description of test cases follows.

The first and only line of each test case contains two integers $a$ and $b$ ($1\le a,b\le 10^9$) — the coordinates of the lattice point where Mary lives.

第一行包含一个整数 $t$（$1 \le t \le 500$），表示测试用例的数量。测试用例的描述如下。

每个测试用例仅有一行，包含两个整数 $a$ 和 $b$（$1\le a,b\le 10^9$），表示玛丽所居住的格点坐标。

For each test case, print an integer $n$ ($1 \le n \le 2$) on the first line, denoting the number of jumps Ian uses in order to meet Mary. Note that you do not need to minimize the number of jumps.

On the $i$-th line of the next $n$ lines, print two integers $0 \le x_i,y_i \le 10^9$ separated by a space, denoting Ian's location $(x_i,y_i)$ after the $i$-th jump. $x_n = a$, $y_n = b$ must hold.

Ian's initial location and his locations after each of the $n$ jumps need not be distinct.

If there are multiple solutions, output any.

对于每个测试用例，在第一行输出一个整数 $n$（$1 \le n \le 2$），表示 Ian 为与 Mary 相遇所使用的跳跃次数。注意：你无需最小化跳跃次数。

在接下来的 $n$ 行中，第 $i$ 行输出两个整数 $0 \le x_i, y_i \le 10^9$，以空格分隔，表示 Ian 在第 $i$ 次跳跃后的位置 $(x_i, y_i)$。必须满足 $x_n = a$ 且 $y_n = b$。

Ian 的初始位置以及他每次跳跃后的位置可以重复（即不必互不相同）。

若存在多个解，输出任意一个即可。

In the first test case:

$(0,0) \to (3,4)$

In the second test case:

$(0,0) \to (3,2) \to (4,4)$

In the third test case:

$(0,0) \to (5,3) \to (3,6)$

第一个测试用例：

$(0,0) \to (3,4)$

第二个测试用例：

$(0,0) \to (3,2) \to (4,4)$

第三个测试用例：

$(0,0) \to (5,3) \to (3,6)$