C. Balanced Team
sortings; two pointers
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).