Minimum Number of Shelves

You are given n books and a list of their difficulty levels. Your task is to determine the minimum number of shelves required to arrange all the books such that books with the same difficulty cannot be placed on the same shelf. In other words, if a particular difficulty level appears multiple times, each occurrence must be on a different shelf.

This is equivalent to finding the maximum frequency of any difficulty level. The answer can be expressed mathematically as:

\( \text{result} = \max_{d \in D} \text{count}(d) \),

where \( \text{count}(d) \) denotes the number of times difficulty level \( d \) appears in the list.

inputFormat

The input is given in stdin and consists of two lines. The first line contains a single integer n (the number of books). The second line contains n space-separated integers representing the difficulty levels of the books.

outputFormat

Output to stdout a single integer representing the minimum number of shelves required.

6
4 3 2 4 1 3

2