Given an array of positive integers. All numbers occur even number of times except one number which occurs odd number of times. Find the number.
Expected Time Complexity: O(n)
Expected Auxiliary Space: Constant
The first line of input contains a single integer T denoting the number of test cases. Then T test cases follow. Each test case consist of two lines.
The first line of each test case consists of an integer N, where N is the size of array.
The second line of each test case contains N space separated integers denoting array elements.
Corresponding to each test case, print in a new line, the number which occur odd number of times.
1 ≤ T ≤ 100
1 ≤ N ≤ 202
1 ≤ A[i] ≤ 1000
8 4 4 8 23