import java.util.*;
public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		
		int x = scan.nextInt();
		int n = scan.nextInt();
		List<Integer> p = new ArrayList<Integer>();
		for(int i=0;i<n;i++) {
			int a = scan.nextInt();
			p.add(a);
		}
		
		
		
		for(int i=0;i<100;i++) {
			if(!p.contains(x-i)) {
				System.out.println(x-i);
				break;
			}else if(!p.contains(x+i)){
				System.out.println(x+i);
				break;
			}
			
		}
		
	}	
	
	
	
}
 

/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