import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        // 整数の入力
        int x = sc.nextInt();
     	for(int i=x;i<x+100002;i++){
         if(isprime(i)){
            System.out.println(i);
           	break;
        }
    }
 }public static boolean isprime(int num){
      boolean isp = true;
      for(int i=2;i<=Math.sqrt(num);i++){
        if (num%i == 0){
        isp = false;
        }
      }
      return isp;
    }
}
/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