시간 제한메모리 제한제출정답맞힌 사람정답 비율
2 초 (추가 시간 없음) 1024 MB133323.077%

## 문제

Given $n$ integers $a_1, a_2, \ldots, a_n$, you want to perform the following operation exactly $n-1$ times.

• Choose two integers $x$ and $y$ in the sequence, remove them, and add a number with the value $x\oplus y$.

Since this alone is just too boring, you can additionally choose a number and add one to it at any moment. You must perform the add-one operation exactly once.

Eventually, only one number will be left in this sequence, and you need to maximize this remaining number. Print the maximum value of the remaining number.

## 입력

The first line of the input contains a single integer $n$ ($1 \le n \le 10^6$).

The next line of the input contains $n$ integers $a_1, a_2, \ldots, a_n$ ($0 \le a_i < 2^{60}$).

## 출력

Output a single line containing a single integer: the maximum value of the remaining number.

## 예제 입력 1

4
1 2 1 2


## 예제 출력 1

7


## 예제 입력 2

5
1 2 3 4 5


## 예제 출력 2

14


## 예제 입력 3

6
1 2 4 7 15 31


## 예제 출력 3

47


## 힌트

In the first example, the optimal strategy is:

• Choose $1$ and $2$: $[\mathbf{1}, \mathbf{2}, 1, 2] \to [1, 2, \mathbf{3}]$
• Choose $1$ and $2$: $[\mathbf{1}, \mathbf{2}, 3] \to [3, \mathbf{3}]$
• Add one to the number $3$: $[\mathbf{3}, 3] \to [3, \mathbf{4}]$
• Choose $3$ and $4$: $[\mathbf{3}, \mathbf{4}] \to [\mathbf{7}]$