Find the Unique Number

Your task is to find the unique integer in an array where every element appears exactly twice except for one element, which appears only once. Using the properties of the \(XOR\) operation, you can achieve this efficiently.

Read the input from stdin and output your answer to stdout.

inputFormat

The input consists of two lines. The first line contains an integer \(n\) denoting the number of integers in the array. The second line contains \(n\) space-separated integers.

outputFormat

Output a single integer which is the unique number in the array.

7
2 3 2 4 4 5 5

3