6876: ABC170 —— C - Forbidden List
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Description
Given are an integer $X$ and an integer sequence of length $N: p_1, \ldots, p_N$.
Among the integers not contained in the sequence $p_1, \ldots, p_N$ (not necessarily positive), find the integer nearest to $X$, that is, find the integer whose absolute difference with $X$ is the minimum. If there are multiple such integers, report the smallest such integer.
Among the integers not contained in the sequence $p_1, \ldots, p_N$ (not necessarily positive), find the integer nearest to $X$, that is, find the integer whose absolute difference with $X$ is the minimum. If there are multiple such integers, report the smallest such integer.
Input
Input is given from Standard Input in the following format:
$X\ N$
$p_1\ \cdots\ p_N$
$X\ N$
$p_1\ \cdots\ p_N$
Output
Print the answer.
Constraints
$1≤X≤100$
$0 \leq N \leq 100$
$1 \leq p_i \leq 100$
$p_1, \ldots, p_N$ are all distinct.
All values in input are integers.
$0 \leq N \leq 100$
$1 \leq p_i \leq 100$
$p_1, \ldots, p_N$ are all distinct.
All values in input are integers.
Sample 1 Input
6 5
4 7 10 6 5
Sample 1 Output
8
Among the integers not contained in the sequence $4, 7, 10, 6, 5$, the one nearest to $6$ is $8$.
Sample 2 Input
10 5
4 7 10 6 5
Sample 2 Output
9
Among the integers not contained in the sequence $4, 7, 10, 6, 5$, the ones nearest to $10$ are $9$ and $11$. We should print the smaller one, $9$.
Sample 3 Input
100 0
Sample 3 Output
100
When $N = 0$, the second line in the input will be empty. Also, as seen here, $X$ itself can be the answer.