import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();

        for (int i = x; i <= 1000000; i++) {
            boolean result = true;
            for (int j = 2; j < i; j++) {
                if (i % j == 0) {
                    result = false;
                }
            }
            if (result) {
                System.out.println(i);
                return;
            }

        }
    }
}
/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