xormax

Task

You are given an integer $N$, followed by $N$ positive integers, the $i$-th number being $v_i$. You are asked to find out the maximum xor sum you can get by choosing a continuous subarray.

A subarray $(L, R)$ is defined as the sequence that contains all values from the $L^{th}$ one to the $R^{th}$ one, and its xor sum is given as $v_L \oplus v_{L+1} \oplus \dots \oplus v_R$, where $\oplus$ is the operator for XOR on bits.

Input data

The first line will contain the integer $N$. The second line will contain $N$ integers.

Output data

The first line will contain the required answer.

Constraints and clarifications

• $1 \leq N \leq 2 \cdot 10^5$
• $0 \leq v_i \leq 10^9$, $1 \leq i \leq N$

Example 1

stdin

6
0 1 2 3 5 4

stdout

6

Explanation

The subarray with the maximum xor sum is $(4, 5)$.

Example 2

stdin

10 
1 2 100 12 3 0 12 4 0 1

stdout

107