##### Time limit: 0.3s

##### Memory limit: 256MB

##### Input:

##### Output:

# 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

- $1 \leq N \leq 10^5$
- $0 \leq v_i \leq 2^{29}$, $1 \leq i \leq N$

# | Points | Constraints |
---|---|---|

1 | 20 | $N \le 500$ |

2 | 20 | $N \le 3\ 000$ |

3 | 60 | No additional constraints |

# 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
```