import java.util.ArrayList;
import java.util.List;
import java.util.Collections;
import java.util.Scanner;

public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    ArrayList<Integer> list = new ArrayList<>();
    int x = sc.nextInt();
    int n = sc.nextInt();
    for(int i=0; i<n; i++){
       list.add(sc.nextInt());
    }

    Collections.sort(list);


    int i = 0;
    int ans = 0;
    while(true){
      if(!(list.contains(x-i))){
        ans = x-i;
        break;
      }

      // for(int j=0; j<list.size(); j++){
      //   System.out.println("*"+list.get(j));
      // }
      if(!(list.contains(x+i))){
        ans = x+i;
        break;
      }
      i++;
    }
    System.out.println(ans);

    //for(int i=0; i<list.size(); i++){
      //System.out.println(list.get(i));
    //}

  }

}
/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