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: Accepted)

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
#include<string.h>
#define BUFSIZE 1000000

int N,K;
int  hoge[BUFSIZE]={0};
long long V,W,T;
int count = 0;
int x,N;
int p[BUFSIZE] = {0};
int rem;
int rem2;

int check(int num) {
  for(int i = 0; i < N;i++){
    if(num == p[i]) return 0;
  }
  printf("%d" ,num);
  exit(0);
}


int main(void){

  scanf("%d %d",&x,&N);
  for(int i = 0; i < N; i++){
    scanf("%d",&p[i]);
  }
  for(int i = 0;i < 100;i++){
      if(check(x-i) == 1 || check(x+i) == 1){

      }
  }

  return 0;
}