Second Highest Score

You are given an integer \( n \) representing the number of scores, followed by a list of \( n \) integers. Your task is to find the second highest unique score among them. If there is no second highest score (i.e. when all scores are identical), output None.

Note: The scores can be very large (up to \(10^9\)), and there might be duplicate values. Ensure that you use efficient methods to avoid performance issues.

inputFormat

The input is read from stdin and is in the following format:

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

outputFormat

Output the second highest unique score to stdout. If there is no second highest unique score, output None.

5
40 75 40 20 100

75