Given an array of integers of size N find minimum xor of any 2 elements.
Example 1:
Input:
N = 3
arr[] = {9,5,3}
Output: 6
Explanation: 
There are 3 pairs -
9^5 = 12
5^3 = 6
9^3 = 10
Therefore output is 6.
Your Task:  
You don't need to read input or print anything. Your task is to complete the function minxorpair() which takes the array arr[], its size N as input parameters and returns the minimum value of xor of any 2 elements.
 
Expected Time Complexity: O(N)
Expected Auxiliary Space: O(N)
 
Constraints:
1 <= N <= 10^{5}
1^{ }<= arr[i] <= 10^{5}