Find the Unique Integer

You are given an array of integers where every integer appears exactly twice except for one unique integer which appears only once. Your task is to find and output that unique integer.

You can solve this problem using the bitwise XOR operation, denoted as \(\oplus\). The XOR operation has the property that \(a \oplus a = 0\) and \(a \oplus 0 = a\). By iteratively applying XOR to all the numbers, the result will be the unique integer.

inputFormat

The input is read from standard input (stdin) and has the following format:

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

outputFormat

Print to standard output (stdout) a single integer — the unique integer that appears only once in the array.

## sample

5
2 3 2 4 4

3

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