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.

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.

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

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).