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

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner scan = new Scanner(System.in);
		
		int x = scan.nextInt();
		int n = scan.nextInt();
		
		ArrayList<Integer> list = new ArrayList<Integer>();
		
		for(int i = 0; i < n; i++) {
			list.add(scan.nextInt());
		}
		
		for(int i = 0; i < 102; i++) {
			if(list.contains(x-i) != true) {
				System.out.print(x-i);
				return;
			}
			else if(list.contains(x+i) != true) {
				System.out.print(x+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