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: Accepted)


import java.util.Scanner;
import java.util.stream.Stream;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int[] line = Stream.of(sc.nextLine().split(" ", 0)).mapToInt(Integer::parseInt).toArray();
		if (line[1] == 0) {
			System.out.println(line[0]);
		} else {
			int[] nums = Stream.of(sc.nextLine().split(" ", 0)).mapToInt(Integer::parseInt).toArray();
			int con = 0;
			boolean isLowerConFlg = false;
			boolean isUpperConFlg = false;
			while (true) {
				isLowerConFlg = false;
				isUpperConFlg = false;

				for (int i = 0; i < nums.length; i++) {
					if (nums[i] == (line[0] - con)) {
						isLowerConFlg = true;
						break;
					}
				}
				if (isLowerConFlg == false) {
					System.out.println(line[0] -con);
					break;
				}
				for (int i = 0; i < nums.length; i++) {
					if (nums[i] == (line[0] + con)) {
						isUpperConFlg = true;
						break;
					}
				}
				if (isUpperConFlg == false) {
					System.out.println(line[0] + con);
					break;
				}
				con++;
			}
		}

	}


}