Book Category Organizer

You are given a collection of books with labels represented by lowercase characters. The problem is to determine the minimum number of categories needed to store these books such that no category contains more than one copy of the same label. In other words, if a particular label appears k times among the books, then at least k categories are required. Formally, if the frequency of a label is given as \(f\), the answer is \(\max{(f)}\) over all labels.

Input Format: The first line contains an integer \(n\) representing the number of books. The second line contains a string \(s\) of length \(n\), where each character represents the label of a book.

Output Format: Output a single integer which is the minimum number of categories needed.

inputFormat

The input consists of two lines. The first line contains a positive integer \(n\) (\(1 \leq n \leq 10^5\)) representing the number of books. The second line contains a string \(s\) of length \(n\) consisting of lowercase English letters, where each letter represents a book label.

outputFormat

Output a single integer — the minimum number of categories needed such that no category has two books with the same label.

## sample

5
abcde

1

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