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();
		int[] numberInfo =  new int[102];
		for(int i=0;i <n;i ++) {
			numberInfo[sc.nextInt()]++;
		}
		if(numberInfo[x] ==0) {
			System.out.println(x);
			return;
		}
		int right = 0;
		for(int i =x+1; i <=101;i++) {
			if(numberInfo[i] ==0) {
				right = i;
				break;
			}
		}
		int left = 0;
		for(int i =x-1; i >=0;i--) {
			if(numberInfo[i] ==0) {
				left = i;
				break;
			}
		}
		if((right -x) >= (x - left)) {
			System.out.println(left);
		}else {
			System.out.println(right);
		}

	}
}
/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