You are given an array a of n integers. Now, let’s define two variables P and S. Where P is the bitwise XOR value of all elements for any non-empty prefix. And S is the bitwise XOR value of all elements for any non-empty suffix. Now find the maximum value of (P&S). Where & denotes the bitwise AND operation.
Note that, the sum of the length of chosen prefix and suffix has to be less than or equal to n.
Input
The first line of the input contains one integer n(2≤n≤106) denoting the number of elements of the array.
The next line contains n space-separated integers a1,a2,…,an(1≤ai≤109) denoting the elements of the array.
Output
Print the maximum value of (P&S) as described in the statement.