Unique Number Finder

Given a list of integers, every element appears exactly three times except for one element which appears only once. Your task is to identify this unique element.

The input begins with an integer n representing the number of elements, followed by n space-separated integers. It is guaranteed that exactly one number occurs once while all others occur exactly three times.

Solve the problem using efficient bit manipulation techniques.

inputFormat

The first line contains an integer n denoting the number of elements in the array. The second line contains n space-separated integers.

outputFormat

Output the single unique integer that appears exactly once in the array.

7
2 2 3 2 4 4 4

3