Eric loves XOR. Eric's friends always ask him doubts related to XOR and he helps them to solve problems but he is busy because of his exams and asks you to help his friends. One of his friends wants your help with the following problem. Given an array of N numbers and a number K. The task is to insert a number in the given array such that the bitwise XOR of all the elements in the new array equals the given input K.
The first line of input contains an integer T denoting the number of test cases.
The first line of each test case consists of 2 integers denoting N and K.
The second line of each test case consists of N-space integers denoting the array.
For each test case print the number by inserting which the XOR of all the elements in the array becomes equal to k.
1 ^ 2 ^ 3 ^ 4 ^ 5 ^ 11 = 10