import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		Scanner stdIn = new Scanner(System.in);
		int x = stdIn.nextInt();
		boolean flag = false;
		
		Outer:while(!flag) {
			for(int i = 2; i < x; i++) {
				if(x % i == 0) {
					x++;
					continue Outer;
				}
			}
			flag = true;
		}
		
		System.out.println(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