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