import java.util.*;
class Main {
    public static void main(String []args) {
        Scanner scn= new Scanner(System.in);
        int x= scn.nextInt();
        int n=scn.nextInt();
        int []arr= new int[n];
        HashSet<Integer> map= new HashSet<>();
        for(int i=0;i<n;i++){
            arr[i]=scn.nextInt();
            map.add(arr[i]);
        }
        int diff=0;
        while(true){
            int no=x-diff;
            if(!map.contains(no)){
                System.out.println(no);
                return;
            }
            no=x+diff;
            if(!map.contains(no)){
                System.out.println(no);
                return;
            }
            diff++;
        }
    }
}
/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