Reversing

An array $A$ holds $N$ numbers, and its indices start at 1. You apply $M$ operations to the array. Write a program that finds the position of the number that started at index $K$ once every operation is done.

One operation is a single nonzero integer $i$. When $i$ is positive, the order of the first $i$ numbers of $A$ is reversed. When $i$ is negative, the order of the last $-i$ numbers is reversed.

For example, take $N = 5$ and $A = [1, 3, 2, 4, 5]$. Applying operation $3$ turns $A$ into $[2, 3, 1, 4, 5]$. Applying operation $-4$ to that reverses the last four numbers and gives $[2, 5, 4, 1, 3]$. The number that started at position 1 moves to position 4, and the number that started at position 3 moves to position 1.

The first line contains the size of the array $N$ ($1 \le N \le 100{,}000$), the position $K$ ($1 \le K \le N$), and the number of operations $M$ ($1 \le M \le 100{,}000$).

The second line contains the numbers stored in $A$, from the first number to the last. Each of those numbers is a natural number no greater than 100,000. The same number may appear in the array several times.

Each of the next $M$ lines contains one integer $i$ describing an operation. $i$ is a nonzero integer whose absolute value is at most $N$.

On the first line, print the position that the $K$th number has moved to after all $M$ operations are done.