CF1427F.Boring Card Game

When they are bored, Federico and Giada often play the following card game with a deck containing $6n$ cards.

Each card contains one number between $1$ and $6n$ and each number appears on exactly one card. Initially the deck is sorted, so the first card contains the number $1$, the second card contains the number $2$, $\dots$, and the last one contains the number $6n$.

Federico and Giada take turns, alternating; Federico starts.

In his turn, the player takes $3$ contiguous cards from the deck and puts them in his pocket. The order of the cards remaining in the deck is not changed. They play until the deck is empty (after exactly $2n$ turns). At the end of the game both Federico and Giada have $3n$ cards in their pockets.

You are given the cards in Federico's pocket at the end of the game. Describe a sequence of moves that produces that set of cards in Federico's pocket.

当感到无聊时，费德里科和贾达经常用一副包含 $6n$ 张牌的纸牌玩以下游戏。

每张牌上印有一个介于 $1$ 到 $6n$ 之间的整数，且每个整数恰好出现在一张牌上。初始时，这副牌是有序排列的：第一张牌上的数字为 $1$，第二张牌上的数字为 $2$，$\dots$，最后一张牌上的数字为 $6n$。

费德里科和贾达轮流进行游戏，费德里科先手。

在自己的回合中，当前玩家从牌堆中取出三张连续的牌，放入自己的口袋中；牌堆中剩余牌的顺序保持不变。他们持续进行游戏，直到牌堆被取空（共恰好 $2n$ 回合）。游戏结束时，费德里科和贾达各自口袋中均有 $3n$ 张牌。

现给出游戏结束时费德里科口袋中的所有牌。请构造一个合法的游戏操作序列，使得最终费德里科口袋中的牌恰好为给定集合。

The first line of the input contains one integer $n$ ($1\le n \le 200$).

The second line of the input contains $3n$ numbers $x_1, x_2,\ldots, x_{3n}$ ($1 \le x_1 \lt x_2 \lt \ldots \lt x_{3n} \le 6n$) – the cards in Federico's pocket at the end of the game.

It is guaranteed that for each test there is at least one sequence of moves that produces such set of cards in Federico's pocket.

输入的第一行包含一个整数 $n$（$1\le n \le 200$）。

输入的第二行包含 $3n$ 个数 $x_1, x_2,\ldots, x_{3n}$（$1 \le x_1 \lt x_2 \lt \ldots \lt x_{3n} \le 6n$），表示游戏结束时 Federico 口袋中的卡片。

保证对于每个测试用例，均存在至少一个操作序列，使得 Federico 的口袋中最终得到这样一组卡片。

Print $2n$ lines, each containing $3$ integers.

The $i$-th line should contain, in increasing order, the integers $a_i \lt b_i \lt c_i$ written on the three cards taken by the player during the $i$-th turn (so taken by Federico if $i$ is odd and by Giada if $i$ is even).

If there is more than one possible sequence of moves, you can print any.

输出 $2n$ 行，每行包含 $3$ 个整数。

第 $i$ 行应按升序包含玩家在第 $i$ 轮所取的三张卡片上的整数 $a_i \lt b_i \lt c_i$（即：若 $i$ 为奇数，则由 Federico 取；若 $i$ 为偶数，则由 Giada 取）。

若存在多种可能的操作序列，输出任意一种即可。

Explanation of the first testcase: Initially the deck has $12 = 2\cdot 6$ sorted cards, so the deck is $[1\ 2\ 3\ 4\ 5\ 6\ 7\ 8\ 9\ 10\ 11\ 12]$.

• During turn $1$, Federico takes the three cards $[9\ 10\ 11]$. After his move, the deck is $[1\ 2\ 3\ 4\ 5\ 6\ 7\ 8\ 12]$.
• During turn $2$, Giada takes the three cards $[6\ 7\ 8]$. After her move, the deck is $[1\ 2\ 3\ 4\ 5\ 12]$.
• During turn $3$, Federico takes the three cards $[2\ 3\ 4]$. After his move, the deck is $[1\ 5\ 12]$.
• During turn $4$, Giada takes the three cards $[1\ 5\ 12]$. After her move, the deck is empty.

At the end of the game, the cards in Federico's pocket are $[2\ 3\ 4\ 9\ 10\ 11]$ and the cards in Giada's pocket are $[1\ 5\ 6\ 7\ 8\ 12]$.

第一个测试用例的解释：初始时，牌堆中有 $12 = 2\cdot 6$ 张已排序的牌，因此牌堆为 $[1\ 2\ 3\ 4\ 5\ 6\ 7\ 8\ 9\ 10\ 11\ 12]$。

• 在第 $1$ 回合中，Federico 拿走了三张牌 $[9\ 10\ 11]$。他操作后，牌堆变为 $[1\ 2\ 3\ 4\ 5\ 6\ 7\ 8\ 12]$。
• 在第 $2$ 回合中，Giada 拿走了三张牌 $[6\ 7\ 8]$。她操作后，牌堆变为 $[1\ 2\ 3\ 4\ 5\ 12]$。
• 在第 $3$ 回合中，Federico 拿走了三张牌 $[2\ 3\ 4]$。他操作后，牌堆变为 $[1\ 5\ 12]$。
• 在第 $4$ 回合中，Giada 拿走了三张牌 $[1\ 5\ 12]$。她操作后，牌堆变为空。

游戏结束后，Federico 口袋中的牌为 $[2\ 3\ 4\ 9\ 10\ 11]$，Giada 口袋中的牌为 $[1\ 5\ 6\ 7\ 8\ 12]$。