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