import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		//100003
		for(int i=n;i<100000;i++) {
			if(sosu(i)) {
				System.out.println(i);
				System.exit(0);
			}
		}
		System.out.println("100003");
		
		sc.close();
	}
	
	public static boolean sosu(int n) {
		
		for(int i=2;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