import java.util.*;
public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int X = sc.nextInt() - 1;
		boolean key = true;
		while (key) {
			X++;
			key = checker(X);
		}
		System.out.println(X);
		
	}
	
	public static boolean checker(int x) {
		for (int i = 2; i <= x/2; i++) {
			if (x%i == 0) {
				return true;
			}
		}
		return false;
	}
}
/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