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 <stdlib.h>
int main(void){
    // Your code here!
    int x, n, mini=100, kouhobig,big,small, kouhomin, onazi=0;
    int p[101];
    scanf("%d%d", &x, &n);
    kouhobig = x;
    kouhomin = x;
    if(n!=0){
    for(int i = 0; i<n; i++){
        scanf("%d", &p[i]);
    }
    }
    else {
        printf("%d", x);
    }
    
    if(n!=0){
  for(int j = 0; j<n; j++){
      if(mini>abs(p[j]-x)){
          mini = abs(p[j]-x);
      if(x == p[j]){
          onazi = 1;
      }
      }
  }
    }
    
    kouhobig = x+mini;
    kouhomin = x-mini;
    big = x+1;
    small = x-1;
        
        for(int l = 0; l < 65535; l++){
            for(int m = 0;m<n;m++){
                if(p[m] =! kouhobig+m && big>kouhobig+m){
                    big = kouhobig+m;
                }
                if(p[m] =! kouhomin-m && small<kouhomin-m){
                    small = kouhomin-m;
                }
            }
        }
        
    if(n!=0){
    if(big+small == 0){
        printf("%d", small);
    }
    else if(abs(big-x)<abs(small-x)){
        printf("%d", big);
    }
    else if(abs(big-x)>abs(small-x)){
        printf("%d", small);
    }
    }
    return 0;
    
}