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();
        int[] Pz = new int[1000];
        for (int i = 0; i < N; i++){
            Pz[sc.nextInt()] = 1;
        }
//        Pz.sort();
        int ans = 0;
        for (int i = 0; i < 101; i++){

            if (Pz[X - i] != 1){
                ans = X - i;
                break;
            }
//            if (X + i > 100){
//                continue;
//            }
            if (Pz[X + i] != 1){
                ans = X + i;
                break;
            }
        }
        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