You are given an array $A$ consisting of $N$ integer values. Find an integer $K$ such that the value of the following function is minimized:

• $\sum_{i = 1}^{i = N} (A[i] \ XOR \ K)$ , $XOR$ represents a bitwise XOR operation

If multiple such $K$ exist, then print the minimum possible value of $K$.

Input format

• The first line contains an integer $T$ denoting the number of test cases. For each test case:
• The first line of each test case contains an integer $N$.
• The second line of each test case contains $N$ space-separated integers denoting array $A$.

Output format

For each test case, print the value of $K$ in a new line.

Constraints 

$1 \le T \le 10 \\ 1 \le N \le 10^5 \\ 1 \le A[i] \le 10^{18}$