import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		while (true) {
			boolean judge = true;
			for (int i = 2; i <= Math.sqrt(N); i++) {
				if (N % i == 0) {
					judge = false;
					break;
				}
			}
			if (judge) {
				break;
			}
			N++;
		}
		System.out.print(N);
	}
}
/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