Problem Statement

You are given a sequence of $N$ non-negative integers $A=(A_1,A_2,\dots,A_N)$. Consider performing the following operation $N-1$ times on this sequence to obtain a sequence of length $1$:

• Let $n$ be the length of $A$. First, rearrange the elements in $A$ in any order you like. Then, replace $A$ with a sequence of $n-1$ non-negative integers $(A_1 \oplus A_2, A_2 \oplus A_3, \dots, A_{n-1} \oplus A_n)$.

Here, $\oplus$ represents the bitwise $\mathrm{XOR}$ operation.

Let $X$ be the value of the term contained in the sequence of length $1$ obtained after $N-1$ operations. Find the maximum possible value of $X$.

What is the bitwise $\mathrm{XOR}$ operation? The bitwise $\mathrm{XOR}$ of two non-negative integers $A$ and $B$, denoted as $A \oplus B$, is defined as follows: In the binary representation of $A \oplus B$, the digit at the $2^k$ ($k \geq 0$) position is $1$ if the digit at the $2^k$ position is $1$ in $A$ or $B$ but not both, and $0$ otherwise. For example, $3 \oplus 5 = 6$ (in binary: $011 \oplus 101 = 110$). In general, the bitwise $\mathrm{XOR}$ of $k$ non-negative integers $p_1, p_2, p_3, \dots, p_k$ is defined as $(\dots ((p_1 \oplus p_2) \oplus p_3) \oplus \dots \oplus p_k)$, and it can be proved that this does not depend on the order of $p_1, p_2, p_3, \dots, p_k$.

Constraints

• $2 \leq N \leq 100$
• $0 \leq A_i < 2^{60}$
• All input values are integers.

Input

The input is given from Standard Input in the following format:

N
A_1 A_2 \dots A_N

Output

Print the answer.