

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


public class Main {

	public static void main(String[] args) {

		Scanner scanner=new Scanner(System.in);


		int x =scanner.nextInt();
		int n =scanner.nextInt();
		ArrayList<Integer> list = new ArrayList<Integer>();
		for(int i=0 ; i<n ; i++) {
			list.add(scanner.nextInt());
		}
		scanner.close();

		int d = 0;
		while(true) {
			if(!list.contains(x-d)) {
				System.out.println(x-d);;
				break;
			}
			if(!list.contains(x+d)) {
				System.out.println(x+d);
				break;
			}
			d++;
		}

	}

}

/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