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)
{
	int X, Y,big, flug,i, str[100];

	for (i = 0; i < 100; i++)
	{
		str[i] = 0;
	}
	scanf("%d%d", &X, &Y);
	for(i=0;i<=Y;i++)
	{
		scanf("%d", &str[i]);
	}
	if (Y == 0)
	{
		printf("%d", X);
	}
	else
	{
		for (i = 0; i < Y; i++)
		{
			while (flug == 0)
			{
				big = str[i];
				flug = 1;
			}
			if (flug == 1 && abs(big - X)  < abs(str[i] - X) )
			{
				big = str[i];
			}
		}
		printf("%d", big);
	}
	return 0;
}