import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		int x = sc.nextInt();
		
		while(true){
			boolean flag = true;
			for(int j = 2; j < Math.sqrt(x); j++){
				if(x%j==0){
					flag = false;
					break;
				}
			}
			if(flag){
				System.out.println(x);
				return;
			}
			x++;
		}



	}

}
/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