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: Wrong Answer)

fun main(args: Array<String>) {
        val (check, numCount) = readLine()!!.split(' ').map { it.toInt() }
        if (numCount == 0) {
            println(check)
            return
        }
        val numbers = readLine()!!.split(' ').map { it.toInt() }.toIntArray()

        var mostLowerResent = 0
        var mostUpperResent = 101
        var lowerDiff = 101
        var upperDiff = 101


        for (i in 1..100) {
            if (numbers.contains(i)) continue
            if (i == check) {
                println(check)
                return
            }
            if (i < check) {
                mostLowerResent = i
                lowerDiff = check - mostLowerResent
            } else {
                mostUpperResent = i
                upperDiff = mostUpperResent - check
                if (lowerDiff <= upperDiff) {
                    break
                }
            }
        }

        if (lowerDiff <= upperDiff) {
            println(mostLowerResent)
        } else {
            println(mostUpperResent)
        }
    }