Count Unique Elements

Given a list of integers, your task is to count the number of unique elements. Formally, let \( S \) be the set obtained from the list of integers. You are required to output \(|S|\), the cardinality of \( S \).

For example, if the input is 1 2 3 4 5, then the number of unique elements is 5, whereas if the input is 1 1 1 1 1 then the answer is 1.

The input will be provided via stdin and the output should be printed to stdout.

inputFormat

The input consists of two lines:

• The first line contains a single integer \( n \) (\(1 \leq n \leq 10^5\)), which is the number of elements in the list.
• The second line contains \( n \) space-separated integers.

outputFormat

Output a single integer denoting the number of unique elements in the list.

5
1 2 3 4 5

5