CF140C.New Year Snowmen

As meticulous Gerald sets the table and caring Alexander sends the postcards, Sergey makes snowmen. Each showman should consist of three snowballs: a big one, a medium one and a small one. Sergey's twins help him: they've already made n snowballs with radii equal to _r_1, _r_2, ..., r__n. To make a snowman, one needs any three snowballs whose radii are pairwise different. For example, the balls with radii 1, 2 and 3 can be used to make a snowman but 2, 2, 3 or 2, 2, 2 cannot. Help Sergey and his twins to determine what maximum number of snowmen they can make from those snowballs.

当一丝不苟的杰拉尔德布置餐桌、体贴的亚历山大寄送明信片时，谢尔盖则在堆雪人。每个雪人必须由三个雪球组成：一个大雪球、一个中等雪球和一个小雪球。谢尔盖的双胞胎兄弟正在帮他：他们已经制作了 $n$ 个雪球，半径分别为 $r_1, r_2, \dots, r_n$。要制作一个雪人，需要任意三个半径两两互不相同的雪球。例如，半径为 $1$、$2$ 和 $3$ 的雪球可以用来制作一个雪人，但半径为 $2$、$2$、$3$ 或 $2$、$2$、$2$ 的雪球则不行。请帮助谢尔盖和他的双胞胎兄弟确定：利用这些雪球最多能制作多少个雪人。

The first line contains integer n (1 ≤ n ≤ 105) — the number of snowballs. The next line contains n integers — the balls' radii _r_1, _r_2, ..., r__n (1 ≤ r__i ≤ 109). The balls' radii can coincide.

第一行包含一个整数 $n$（$1 \leq n \leq 10^5$）—— 雪球的数量。
第二行包含 $n$ 个整数 —— 各雪球的半径 $r_1, r_2, \dots, r_n$（$1 \leq r_i \leq 10^9$）。
雪球的半径可以相同。

Print on the first line a single number k — the maximum number of the snowmen. Next k lines should contain the snowmen's descriptions. The description of each snowman should consist of three space-separated numbers — the big ball's radius, the medium ball's radius and the small ball's radius. It is allowed to print the snowmen in any order. If there are several solutions, print any of them.

第一行输出一个整数 $k$ —— 最多能堆出的雪人的个数。接下来的 $k$ 行，每行描述一个雪人：包含三个用空格分隔的数字，分别表示大球、中球和小球的半径。雪人的输出顺序可以任意。若存在多种方案，输出任意一种即可。