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 C (GCC 9.2.1) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <math.h>

int main()
{
  int x,n;
  scanf("%d%d",&x,&n);
  int p[n];
  int i;
  i = 0;
  while (i < n)
  {
    scanf("%d",&p[i]);
    i++;
  }
  i = -100;
  int j;
  j = 0;
  int ans;
  ans = -300;
  while (i >= -100 && i <= 200)
  {
    j = 0;
    while (j < n)
    {
      //printf("%d",ans);
      if (i == p[j])
      {
        break;
      }
      if (j == n - 1)
      {
        //printf("%d",abs(x - ans));
        if (abs(x - ans) > abs(x - i))
        {
          ans = i;
        }
      }
      j++;
    }
    i++;
  }
  printf("%d",ans);
}