Single Number

Given an array of integers where every element appears twice except for one, your task is to find that unique element which appears only once.

You are provided with an array of n integers. It is guaranteed that exactly one element appears only once while all the other elements appear exactly twice.

You are required to read input from standard input and write the result to standard output.

Note: The intended solution involves using the XOR operation, exploiting the fact that x^x=0 and x^0=x.

inputFormat

The first line of input contains a single integer n, representing the number of elements in the array.

The second line contains n space-separated integers.

outputFormat

Output a single integer, the element that appears only once in the array.

3
2 2 1

1