Nikitosh the painter has a 1-indexed array A of N elements. He wants to find the maximum value of expression

(A[l₁] ⊕ A[l₁ + 1] ⊕ ... ⊕ A[r₁]) + (A[l₂] ⊕ A[l₂ + 1] ⊕ ... ⊕ A[r₂]) where 1 ≤ l₁ ≤ r₁ < l₂ ≤ r₂ ≤ N.

Here, x ⊕ y means the bitwise XOR of x and y.

Because Nikitosh is a painter and not a mathematician, you need to help him in this task.

Input

The first line contains one integer N, denoting the number of elements in the array.

The second line contains N space-separated integers, denoting A₁, A₂, ... , A_N.

Output

Output a single integer denoting the maximum possible value of the given expression.

Constraints

• 2 ≤ N ≤ 4*10⁵
• 0 ≤ A_i ≤ 10⁹

Subtasks

• Subtask 1 (40 points) : 2 ≤ N ≤ 10⁴
• Subtask 2 (60 points) : Original constraints

Example

Input:
5
1 2 3 1 2
Output:
6

Explanation

Choose (l₁, r₁, l₂, r₂) = (1, 2, 3, 3) or (1, 2, 4, 5) or (3, 3, 4, 5).