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 Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

import java.util.ArrayList;
import java.util.Scanner;


public class Main {


//	final int MOD = 1000000007;

//	public static int min = 3000000;

	public static void main(String[] args) {

		int ans = 0;
		Scanner sc = new Scanner(System.in);
		boolean f = false;

//		long k = sc.nextLong();
		int x = sc.nextInt();
		int n = sc.nextInt();

		int[] a = new int[n];
		ArrayList<Integer> list = new ArrayList<>();
		for (int i = 0; i < n; i++) {
			int t = sc.nextInt();
			a[i] = t;
			list.add(t);
		}

		//-------------------------------------------------------------------------------------
		int tmp = 10000;
		for(int i = 1; i <= 100; i++) {
			if(list.contains(i))
				continue;
			if(tmp > Math.abs(x - i)) {
				ans = i;
				tmp = Math.abs(x - i);
			}
		}

		//-------------------------------------------------------------------------------------

//		if(f) {
//			System.out.println("Yes");
//		} else {
//			System.out.println("No");
//		}

		System.out.println(ans);

		sc.close();
	}



}