import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int number = sc.nextInt();
		int numlength = sc.nextInt();
		boolean[] numbers = new boolean[101];

		for (int i = 0; i < numlength; i++) {
			numbers[sc.nextInt()] = true;
		}

		for (int i = 0; i < numlength + 1; i++) {
			if (numbers[number - i] == false) {
				System.out.println(number - i);
				return;
			} else if(number + i == 101){
				System.out.println(101);
				return;
			}else if (numbers[number + i] == false) {
				System.out.println(number + i);
				return;
			}
		}

	}

}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz