One Odd Occurring

Given an array ‘ARR’ of ‘N’ integers, where all the elements occur an even number of times and only one number occurs an odd number of times. Find the number which occurs an odd number of times.

EXAMPLE:

Input: 
'N' = 5
'ARR' = 1 2 3 2 3

Output: 1

Except for number 1 all numbers occur even number of times.

Input Format :

The first line will contain integer 'T', the number of test cases. For each test case, there will be only two lines.

The first line contains a single integer, 'N' representing the size of the array.
The second line contains ‘N’ spaced integers.

Output format :

For each test case, print a single integer representing the number occurring odd number of times.

Note :

You don't need to print anything. It has already been taken care of. Just implement the given function.

Constraints :

1 <= 'T' <= 10
1 <= 'N' <= 10^4
1 <= ARR[i] <= 10^5
Time Limit: 1 sec

Sample Input 1 :

2
9
4 5 6 5 6 9 9 4 4
5
1 1 10 10 19

Sample Output 1 :

4
19

Explanation Of Sample Input 1 :

For the first test case, 5, 6, and 9 occur even number of times and only 4 occur odd number of times.

For the second test case, only 19 occur odd number of times.

Sample Input 2 :

2
5
1 1 1 1 1
7
1 1 1 1 2 3 3

Sample Output 2 :

1
2