import java.util.Arrays;
import java.util.LinkedList;
import java.util.Scanner;

public class Main {
	
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		
		final int N = sc.nextInt();
		
		for(int cur = N - 100; cur <= N + 100; cur++){
			boolean ok = false;
			for(int div = 2; div < cur; div++){
				if(cur % div == 0){
					ok = true;
					break;
				}
			}
			
			if(ok){
				System.out.println(cur);
				break;
			}			
		}
	}
	
}