import java.util.Scanner;
//EphSon solution

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int x=sc.nextInt();
        int n=sc.nextInt();
        int[] p=new int[n];
        for(int i=0;i<n;i++) {
        	p[i]=sc.nextInt();
        }
        for(int i=0;i<=100;i++) {
        	int num1=x-i,num2=x+i;
        	int count1=0,count2=0;
        	for(int j=0;j<n;j++) {
        		if(p[j]==num1)	count1++;
        		if(p[j]==num2)	count2++;
        	}
        	if(count1==0) {
        		System.out.println(num1);
        		break;
        	}else if(count2==0) {
        		System.out.println(num2);
        		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