import java.util.*;

public class Main {
	public static void main(String[] args) throws Exception{
		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();
		}
      	int ans = x;
      	int num = x;
      	for(int i=0; i<n; i++){
          if(ans==p[i]){
            ans++;
            i=-1;
          }
        }
      	for(int i=0; i<n; i++){
          if(num==p[i]&&ans>0){
            num--;
            i=-1;
          }
        }
      	if(Math.abs(ans-x)>=Math.abs(num-x)) {
		    System.out.println(num);
		}else {
			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