import java.util.*;
import java.util.stream.*;
class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int X = sc.nextInt();
    int N = sc.nextInt();
    sc.nextLine();
    List<Integer> P = new ArrayList<>();
    for (int i = 0; i < N; i++) P.add(sc.nextInt());
    int ans = 0;
    int min = X;
    for (int i = 0; i <= 101; i++) {
      if (P.contains(i)) continue;
      if (min > Math.abs(X-i)) {
        ans = i;
        min = Math.abs(X-i);
      }
    }
    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