import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        
        //与えられた数が素数か素数でないかを見分けるには，2からN−1までの整数で割り切れるかどうか
        for (int n=x; ; n++) {
            if (judgeNumber(n)) {
                System.out.println(n);
                break;
            }
        }
    }
    
    private static boolean judgeNumber(int n) {
        for (int i=2; i<=n-1; i++) {
            if (n%i == 0){
                return false;
            }
        }
        return true;
    }
}
/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