import java.util.Scanner;
public class Main{
 public static void main(String[] args){
   Scanner sc = new Scanner(System.in);
   int X = sc.nextInt();
   boolean br = true;
   
   while(br)
   {
     br=false;
     for(int i=2;i<=Math.sqrt(X);i++)
     {
       if(X%i==0)
       {
         br=true;
         break;
       }
     }     
     X++;
   }
   X--;
   System.out.println(X);
 }
}
/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