Given an array of non-negative integers, find two disjoint subarrays of the array such that the xor of their respective sums is maximum possible and print the maximum possible value.

In other words, given an array consisting of n integers a1,a2,..an, find out the maximum value of (sum(l1,r1) xor sum(l2,r2) ), 1≤l1≤r1 < l2≤r2≤n, where sum(l,r) denotes sum of elements from indices l to r, both inclusive.

Input Format:
The first line contains an integer n, denoting the number of elements in the array.
The second line contains n space separated integers a1,a2,..an.

Output Format:
Output the required value.

Constraints:
1≤n≤900
1≤ai≤100