import java.util.Scanner;

public class HelloWorld{

     public static void main(String []args){
          Scanner in = new Scanner(System.in);
         int n = in.nextInt();
         int s = 0; 
         int k=0;
         while (k!=1) {
             k = 0;
             int i=1;
             n+=1;
             while(i!=n-1){
                if (n%i==0){
                    k+=1;
                
                }
                i++;
             }
         }
        System.out.println(n);
         }
     }