import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    long x = sc.nextLong();
    if(x==2){
      System.out.println(2);
      return;
    }
    for(long i=x;i<x*5;i++){
      boolean flag = true;
      for(int j=2;j<=Math.sqrt(i);j++){
        if(i%j==0)flag=false;
      }
      if(flag){
        System.out.println(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