import java.util.Arrays;
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();
		Integer nList[]	= new Integer[N];
		for(int i = 0; i < N; i++) {
			nList[i]	= sc.nextInt();
		}
		int ans			= X;
		Boolean flag	= true;
		for (int i = 0; i <= X && flag; i++) {
			if(!(Arrays.asList(nList).contains(X-i))) {
				ans = X-i;
				flag = false;
			}
			else if(!(Arrays.asList(nList).contains(X+i))) {
				ans =X+i;
				flag = false;
			}
		}
		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