CF1133C.Balanced Team

You are a coach at your local university. There are $n$ students under your supervision, the programming skill of the $i$-th student is $a_i$.

You have to create a team for a new programming competition. As you know, the more students some team has the more probable its victory is! So you have to create a team with the maximum number of students. But you also know that a team should be balanced. It means that the programming skill of each pair of students in a created team should differ by no more than $5$.

Your task is to report the maximum possible number of students in a balanced team.

你是一所本地大学的教练。你手下有 $n$ 名学生，第 $i$ 名学生的编程能力为 $a_i$。

你需要为一场新的编程竞赛组建一支队伍。众所周知，一支队伍的学生人数越多，获胜的可能性就越大！因此，你需要组建一支学生人数最多的队伍。但你也知道，一支队伍应当是“平衡”的：即队伍中任意两名学生的编程能力之差至多为 $5$。

你的任务是报告一支平衡队伍中可能包含的学生最大人数。

The first line of the input contains one integer $n$ ($1 \le n \le 2 \cdot 10^5$) — the number of students.

The second line of the input contains $n$ integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 10^9$), where $a_i$ is a programming skill of the $i$-th student.

输入的第一行包含一个整数 $n$（$1 \le n \le 2 \cdot 10^5$）—— 学生的数量。

输入的第二行包含 $n$ 个整数 $a_1, a_2, \dots, a_n$（$1 \le a_i \le 10^9$），其中 $a_i$ 表示第 $i$ 个学生的编程能力。

Print one integer — the maximum possible number of students in a balanced team.

输出一个整数——平衡团队中学生数量的最大可能值。

In the first example you can create a team with skills $[12, 17, 15]$.

In the second example you can take all students in a team because their programming skills are equal.

In the third example you can create a team consisting of a single student (and you cannot create a team consisting of at least two students).

在第一个例子中，你可以组建一支技能为 $[12, 17, 15]$ 的队伍。

在第二个例子中，你可以将所有学生都纳入一支队伍，因为他们的编程技能均相等。

在第三个例子中，你可以组建一支仅包含一名学生的队伍（但无法组建一支至少包含两名学生的队伍）。