Description

In this question, we define a bracket string that meets the following requirements as a "legal bracket string":

1. () is a "legal bracket string".
2. If A is a "legal bracket string", then (A) is also a "legal bracket string".
3. If A and B are both "legal bracket strings", then AB is also a "legal bracket string".

The definition of substring and different substring in this question is as follows:

1. We use $S(l,r)$ ($1\le l \le r \le |S|$, which $|S|$ is the length of $S$) to represent a substring of $S$. It means a string consisting of any consecutive characters from $l$ to $r$ in $S$.
2. Two substrings of S are considered different if and only if their positions in S are different, (i.e. $l$ is different or $r$ is different).

Little Q has a rooted tree which rooted at node $1$ and the number of nodes is $n$. Except for node $1$, the parent node of node $u(2\le u\le n)$ is $f_u(1\le f_u < u)$.

Little Q finds that there is exactly one bracket on each node of this tree, which may be ( or ). He defines $s_i$ as a string composed of brackets on the simple path from the root node to the node $i$ and arranged in sequence according to the sequence of the nodes.

Obviously $s_i$ is a bracket string, but it may not be a "legal bracket string". So now Little Q wants to find out how many different substrings of $s_i$ are "legal bracket strings" for all $i(1\le i\le n)$.

Assuming that there are $k_i$ different substrings of $s_i$ as "legal bracket strings", you only need to tell Little Q the bitwise XOR of all $i\times k_i$, which is:

$$(1\times k_1)\operatorname{xor}(2\times k_2)\operatorname{xor}(3\times k_3)\operatorname{xor}\cdots\operatorname{xor}(n\times k_n)$$

Among them, $\text{xor}$ is bitwise XOR operation.

Input Format

The first line contains an integer $n$, which represents the number of nodes in the tree.

The second line contains an bracket string of length $n$, which the $i$-th bracket represents the bracket on the $i$-th node.

The third line contains $n-1$ integer. The $i$-th integer represents the father of $(i+1)$-th node $f_{i+1}$.

Output Format

Print one integer in a single line, which is the answer.

5
(()()
1 1 2 2

6

The shape of the tree is as follows:

• The brackets on the simple path from the root to node $1$ are arranged in order to form a string of (, and the number of substrings that are "legal bracket strings" is $0$.
• The brackets on the simple path from the root to node $2$ are arranged in order to form a string of ((, and the number of substrings that are "legal bracket strings" is $0$.
• The brackets on the simple path from the root to node $3$ are arranged in order to form a string of (), and the number of substrings that are "legal bracket strings" is $1$.
• The brackets on the simple path from the root to node $4$ are arranged in order to form a string of (((, and the number of substrings that are "legal bracket strings" is $0$.
• The brackets on the simple path from the root to node $5$ are arranged in order to form a string of ((), and the number of substrings that are "legal bracket strings" is $1$.

Sample 2

See attached files brackets2.in and brackets2.ans.

Sample 3

See attached files brackets3.in and brackets3.ans.

Constraints