CF1413A.Finding Sasuke

Naruto has sneaked into the Orochimaru's lair and is now looking for Sasuke. There are $T$ rooms there. Every room has a door into it, each door can be described by the number $n$ of seals on it and their integer energies $a_1$, $a_2$, ..., $a_n$. All energies $a_i$ are nonzero and do not exceed $100$ by absolute value. Also, $n$ is even.

In order to open a door, Naruto must find such $n$ seals with integer energies $b_1$, $b_2$, ..., $b_n$ that the following equality holds: $a_{1} \cdot b_{1} + a_{2} \cdot b_{2} + ... + a_{n} \cdot b_{n} = 0$. All $b_i$ must be nonzero as well as $a_i$ are, and also must not exceed $100$ by absolute value. Please find required seals for every room there.

鸣人潜入了大蛇丸的巢穴，现在正在寻找佐助。巢穴中共有 $T$ 个房间。每个房间都有一扇门，每扇门可用其上的封印数量 $n$ 及其整数能量值 $a_1$, $a_2$, ..., $a_n$ 来描述。所有能量值 $a_i$ 均非零，且其绝对值不超过 $100$；此外，$n$ 为偶数。

为了打开一扇门，鸣人必须找到 $n$ 个具有整数能量值 $b_1$, $b_2$, ..., $b_n$ 的封印，使得以下等式成立：

$$a_{1} \cdot b_{1} + a_{2} \cdot b_{2} + ... + a_{n} \cdot b_{n} = 0.$$

所有 $b_i$ 也必须非零（与 $a_i$ 相同），且其绝对值同样不得超过 $100$。请为每个房间找出满足要求的封印。

The first line contains the only integer $T$ ($1 \leq T \leq 1000$) standing for the number of rooms in the Orochimaru's lair. The other lines contain descriptions of the doors.

Each description starts with the line containing the only even integer $n$ ($2 \leq n \leq 100$) denoting the number of seals.

The following line contains the space separated sequence of nonzero integers $a_1$, $a_2$, ..., $a_n$ ($|a_{i}| \leq 100$, $a_{i} \neq 0$) denoting the energies of seals.

第一行包含唯一一个整数 $T$（$1 \leq T \leq 1000$），表示大蛇丸巢穴中的房间数量。其余各行描述各扇门。

每扇门的描述以一行开头，该行包含唯一一个偶数 $n$（$2 \leq n \leq 100$），表示封印的数量。

接下来的一行包含由空格分隔的非零整数序列 $a_1$, $a_2$, ..., $a_n$（$|a_{i}| \leq 100$，且 $a_{i} \neq 0$），表示各封印的能量值。

For each door print a space separated sequence of nonzero integers $b_1$, $b_2$, ..., $b_n$ ($|b_{i}| \leq 100$, $b_{i} \neq 0$) denoting the seals that can open the door. If there are multiple valid answers, print any. It can be proven that at least one answer always exists.

对于每扇门，输出一个由空格分隔的非零整数序列 $b_1$, $b_2$, ..., $b_n$（满足 $|b_{i}| \leq 100$ 且 $b_{i} \neq 0$），表示能够打开该门的封印。若存在多个合法答案，输出任意一个即可。可以证明至少存在一个答案。

For the first door Naruto can use energies $[-100, 1]$. The required equality does indeed hold: $1 \cdot (-100) + 100 \cdot 1 = 0$.

For the second door Naruto can use, for example, energies $[1, 1, 1, -1]$. The required equality also holds: $1 \cdot 1 + 2 \cdot 1 + 3 \cdot 1 + 6 \cdot (-1) = 0$.

对于第一扇门，鸣人可以使用的能量为 $[-100, 1]$。所要求的等式确实成立：$1 \cdot (-100) + 100 \cdot 1 = 0$。

对于第二扇门，鸣人可以使用例如能量 $[1, 1, 1, -1]$。所要求的等式也成立：$1 \cdot 1 + 2 \cdot 1 + 3 \cdot 1 + 6 \cdot (-1) = 0$。