import java.util.*;

public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            int X = Integer.parseInt(sc.next());
            int N = Integer.parseInt(sc.next());
            boolean[] p = new boolean[102];

            for (int i = 0; i < N; i++) {
                 p[Integer.parseInt(sc.next())] = true;
            }
            for (int i = 0; i <= 50; i++) {
                if (X - i >= 0 && !p[X - i]) {
                    System.out.println(X - i);
                    return;
                }
                if (X + i <= 101 && !p[X + i]) {
                    System.out.println(X + i);
                    return;
                }
            }
        }
    }
}

/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