import java.util.*;
 
public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    int x;
    x=scan.nextInt();


    for(int j=0;j<100;j++){
      if(isPrime(x+j)){
        System.out.println(x+j);
        return;
      }
    }
    //System.out.println(5+" sqrt "+Math.sqrt(5)+ " isp "+isPrime(5));
  }

  public static Boolean isPrime(int a){
    if(a<2){
      return false;
    }
    for(int i=2;i<=Math.sqrt(a);i++){
      if(a%i==0){
        return false;
      }
    }
    return true;
  }
}
/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