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

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int x = sc.nextInt();
		int n = sc.nextInt();
		List<Integer> list = new ArrayList<>();
		int ans = x;

		for (int i = 0; i < n; i++) {
			list.add(sc.nextInt());
		}

		for (int dif = 0; dif <= n; dif++) {

			//x-difがリストに無いとき
			if (!list.contains(x - dif)) {
				ans = x - dif;
				break;
			}

			//x+difがリストに無いとき
			if (!list.contains(x + dif)) {
				ans = x + dif;
				break;
			}

		}

		System.out.println(ans);

	}

}

/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