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 Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

import java.util.Scanner;

class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    byte x = sc.nextByte();
    byte n = sc.nextByte();
    if(n > 0) {
      boolean[] num = new boolean[101];
      byte li = 101;
      byte ui = 0;
      for(byte i = 0; i < n; i++) {
        byte val = sc.nextByte();
        if(li > val) li = val;
        if(ui < val) ui = val;
        num[val] = true;
      }
      sc.close();
      if(li > 1) li--;
      if(ui < 100) ui++;
      byte cl = 0;
      byte cld = 101;
      for(byte i = li; i <= ui; i++) {
        if(!num[i]) {
          byte nd = (byte)Math.abs((int)(x - i));
          if(cld > nd) {
            cld = nd;
            cl = i;
          }
        }
      }
      System.out.println(cl); 
    } else {
      System.out.println(x);
    }
  }
}