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: Accepted)

import java.util.*;
public class Main {
    public static void main(String args[]) {
  Scanner sc = new Scanner(System.in);
  int x = sc.nextInt();
  int n = sc.nextInt();
  
  boolean[] ok = new boolean[201];
  for(int i =0;i<n;i++){
      int c = sc.nextInt();
      ok[c] =true;
  }
  int result = 500;
  int diff = 500;
  for(int i =0;i<=200;i++){
      if(!ok[i]){
          int abs = Math.abs(x-i);
          if(abs<diff){
              result =i;
              diff = abs;
          }else if(abs == diff){
                result = Math.min(result, i);
          }
      }
  }
  System.out.println(result);
    }
}