package yukicoder;

import java.util.Scanner;

public class Yuki12 {
    
    public static void main( String[] args ) {
        
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        scan.close();
                
        for ( int i = (n - 100); i <= n + 100; i++ ) {
            
            if(i<=3){
                continue;
            }
                        
            if(check(i)){
                break;			
            }
        }
    }
    
    public static boolean check(int num) {
        
        for (int i=2; i < num; i++ ) {
            
            if (num%i == 0){
                System.out.println(num);
                return true;
            }
        }
        return false;
    }

}