Problem:
Score : 300 points

Problem Statement

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.

Constraints

1 \leq X \leq 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.

Input

Input is given from Standard Input in the following format:

X N
p_1 ... p_N

Output

Print the answer.

Sample Input 1

6 5
4 7 10 6 5

Sample Output 1

8

Among the integers not contained in the sequence 4, 7, 10, 6, 5, the one nearest to 6 is 8.

Sample Input 2

10 5
4 7 10 6 5

Sample Output 2

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 Input 3

100 0

Sample Output 3

100

When N = 0, the second line in the input will be empty. Also, as seen here, X itself can be the answer.

Solution in Kotlin (1.3.71) (judge verdict: Accepted)

import kotlin.math.abs

fun main() {
    val (X, N) = readLine()?.split(" ")?.map { Integer.parseInt(it) } ?: return
    if (N == 0) {
        println(X)
        return
    }
    val p = readLine()?.split(" ")?.map { Integer.parseInt(it) }?.sorted() ?: return
    var frag: Boolean
    val num = intArrayOf(Integer.MAX_VALUE, 0)
    for (i in 0..p[p.size - 1]+1) {
        frag = true
        for (j in p) {
            if (j == i) {
                frag = false
                break
            }

        }
        if (frag) {
            if (abs(X - i) < num[0]) {
                num[0] = abs(X - i)
                num[1] = i
            }
        }
    }
    println(num[1])
}