Problems
Figurines
Figurines
Bob has a lot of mini figurines. He likes to display some of them on a shelf above his computer screen and he likes to regularly change which figurines appear. This ever-changing decoration is really enjoyable. Bob takes care of never adding the same mini figurine more than once. Bob has only $n$ mini figurines and after $n$ days he arrives at the point where each of the $n$ figurines have been added and then removed from the shelf (which is thus empty).
Bob has a very good memory. He is able to remember which mini figurines were displayed on each of the past days. So Bob wants to run a little mental exercise to test its memory and computation ability. For this purpose, Bob numbers his figurines with the numbers $0, ..., n - 1$ and selects a sequence of $n$ integers $d_0, ..., d_{n-1}$ all in the range $[0; n]$. Then, Bob computes a sequence $x_0, . . . , x_n$ in the following way: $x_0 = 0$ and $x_{i+1} = (x_i + y_i)~mod~n$ where mod is the modulo operation and $y_i$ is the number of figurines displayed on day $d_i$ that have a number higher or equal to $x_i$. The result of Bob's computation is $x_n$.
More formally, if we note $S(i)$ the subset of $\{0, ..., n - 1\}$ corresponding to figurines displayed on the shelf on day $i$, we have:
\begin{itemize}
\item $S(0)$ is the empty set;
\item $S(i)$ is obtained from $S(i - 1)$ by inserting and removing some elements.
\end{itemize}
Each element $j~(0 \le j < n)$ is inserted and removed exactly once and thus, the last set $S(n)$ is also the empty set. The computation that Bob performs corresponds to the following program:
$~~~~~x_0 = 0$
$~~~~~for~i \in [0; n - 1]$
$~~~~~~~~~~x_{i+1} = (x_i + \#\{y \in S(d_i)~such~that~y \ge x_i\})~mod~n$
$~~~~~output~x_n$
Bob asks you to verify his computation. For that he gives you the numbers he used during its computation (the $d_0, ..., d_{n-1})$ as well as the log of which figurines he added or removed every day. Note that a mini figurine added on day $i$ and removed on day $j$ is present on a day $k~(i \le k < j)$. You should tell him the number that you found at the end of the computation.
\InputFile
The input is composed of $2 \cdot n + 1$ lines.
\begin{itemize}
\item The first line contains the integer $n~(1 \le n \le 10^5)$.
\item Lines $2$ to $n + 1$ describe the figurines added and removed. Line $i + 1$ contains space-separated $+j$ or $-j$, $0 \le j < n$, to indicate that $j$ is added or removed on day $i$. This line may be empty. A line may contain both $+j$ and $-j$, in that order.
\item Lines $n + 2$ to $2 \cdot n + 1$ describe the sequence $d_0, ..., d_{n-1}$. Line $n + 2 + i$ contains the integer $d_i~(0 \le d_i \le n)$.
\end{itemize}
\OutputFile
The output should contain a single line with a single integer which is $x_n$.
\Examples
The output is $2$ since
\begin{itemize}
\item first, $x = 2$ since $S(1) = \{0, 2\}$ and $\#\{y \in S(1)~such~that~y > 0\} = 2$;
\item then, $x = 0$ since $S(2) = \{1, 2\}$ and $\#\{y \in S(2)~such~that~y > 2\} = 1$;
\item and finally, $x = 2$ since $S(2) = \{1, 2\}$ and $\#\{y \in S(2)~such~that~y > 0\} = 2$.
\end{itemize}
Input example #1
3 +0 +2 -0 +1 -1 -2 1 2 2
Output example #1
2