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

public class Main {

	public static void main(final String[] args) {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt(), n = sc.nextInt();
		int[] a = new int[n];
		List<Integer> list = new ArrayList<Integer>();
		for (int i = 0; i < n; i++) {
			list.add(sc.nextInt());
		}
		int r = Integer.MAX_VALUE;
		int res = -1;
		for (int i=-5;i<=100+5;i++) {
			if (!list.contains(i)) {
			int t = Math.abs(i - x);
				if (r > t) {
					r = t;
					res = i;
				}
			}
		}
		System.out.println(res);
	}
}

/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