package yukicoder192;
import java.util.Scanner;
public class Main {
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		for(int i=-100;i<=100;i++){
			for(int j=2;j<=n+i;j++){
				if((n+i)%j==0){
					System.out.println(n+i);
					return;
				}
			}
		}
	}
}