import java.util.*;
public class Main{
  public static void main(String args[]){
      int i,x,n;
      Scanner scn =new Scanner(System.in);
      x=scn.nextInt();
      n=scn.nextInt();
      int[] a= new int[n];
      HashMap<Integer,Boolean> map = new HashMap<>();
      for(i=0;i<n;i++){
         a[i]=scn.nextInt();
         map.put(a[i],true);
       }
      int check = x;
      int diff =0;

       while(true){
          if(!map.containsKey(check-diff)){
             System.out.println(check-diff);
             break;
           }
           
          else if(!map.containsKey(check+diff)){
             System.out.println(check+diff);
             break;
           }
           
           else diff++;
        }
   }
}



/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