P8778 [AtCoder] diverta 2019 Programming Contest - XOR Partitioning
普及
题目描述

The beauty of a sequence a of length n is defined as $a_1 \oplus \cdots \oplus a_n$, where $\oplus$ denotes the bitwise exclusive or (XOR).

You are given a sequence A of length N. Snuke will insert zero or more partitions in A to divide it into some number of non-empty contiguous subsequences.

There are 2^{N-1} possible ways to insert partitions. How many of them divide A into sequences whose beauties are all equal? Find this count modulo 10^{9}+7.

Constraints

  • All values in input are integers.
  • $1 \leq N \leq 5 \times 10^5$
  • $0 \leq A_i < 2^{20}$

Input

Input is given from Standard Input in the following format:

N
$A_1 A_2 \ldots A_{N}$

Output

Print the answer.

Examples

Input

3
1 2 3

Output

3

Input

3
1 2 2

Output

1

Input

32
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Output

147483634

Input

24
1 2 5 3 3 6 1 1 8 8 0 3 3 4 6 6 4 0 7 2 5 4 6 2

Output

292

输入格式

见题面

输出格式

见题面

样例输入
32 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
样例输出
147483634