Cyclical Permutation Check

You are given n integers. Your task is to determine whether a cyclical permutation of these integers can be formed such that the arrangement is valid under the following simple criterion:

A cyclical permutation is possible if and only if all the numbers are distinct. In other words, if every number appears exactly once, then output YES; otherwise, output NO.

Explanation:

• If the list contains unique numbers, then it is possible to arrange them in a circle without any repeated element next to each other.
• If any number is repeated, then a valid cyclical permutation cannot be formed.

This simple criterion is derived from the observation that for a cyclical permutation to be valid, every number's uniqueness is a necessary condition. Mathematically, if we let \( S \) be the set of given numbers and \( n \) be the total count, then a cyclical permutation exists if and only if \(|S| = n\).

inputFormat

The first line contains an integer (n) representing the number of integers. The second line contains (n) space-separated integers.

outputFormat

Output a single line: "YES" if a cyclical permutation can be formed (i.e., all numbers are unique), otherwise "NO".## sample

1
1

YES