import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        new Main().run();
    }

    public void run() {
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        System.out.println(getNextPrimeNumber(X));

    }

    public int getNextPrimeNumber(int num) {
        int i = num;
        while (true) {
            boolean isPrime = true;
            for (int j = 2; j < i; j++) {
                if (i % j == 0) {
                    isPrime = false;
                    break;
                }
            }
            if (isPrime) {
                return i;
            }
            i++;
        }
    }
}
/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