import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();

        for(long i = N; i < 10000000; i++) {
            if(isPrime(i)) {
                System.out.println(i);
                break;
            }
        }

    }
    public static boolean isPrime(long N) {
        if(N == 1) return false;
        for(long i = 2; i * i <= N; 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