import java.util.*;
public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int X = sc.nextInt();
    int N = sc.nextInt();
    Integer[] p = new Integer[N];
    for(int i=0;i<N;i++){
      p[i] = sc.nextInt();
    }
    int i=0;
    int abs = 0;
    while(true){
      if(!(Arrays.asList(p).contains(X-i))){
        abs = -i;
        break;
      }else if(!(Arrays.asList(p).contains(X+i))){
        abs = i;
        break;
      }
      i++;
    }
    System.out.println(X+abs);
  }
}
/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