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>

int main(){
    int x,n;
    scanf("%d%d",&x,&n);
   
    int a[n];
    for(int i=0;i<n;i++)
    scanf("%d",&a[i]);
    int l,h;
    l=x;
    h=x;
    while(1){
        int countL=0,countH=0;
        for(int i=0;i<n;i++){
            if(l==a[i]){
                countL++;
            }
            if(h==a[i])
            countH++;
        }
        if(countL>0 && countH>0){
            l--;
            h++;
        }
        else if(countL==0){
            printf("%d",l);
            return 0;
        }
        else if(countH==0){
            printf("%d",h);
            return 0;
        }
        
       
    }
}