import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		if(N == 2) System.out.println(N);
		else {
			System.out.println(prime(N));
		}
		
	}
	public static int prime(int n) {
		boolean check = false;
		int count = 0;
		int ans = 0;
		int j = 0;
		
		while(ans == 0) {
			ans = n+j;
			for(int i = 2; i < n + j -1; i++) {
				if((n+j)%i == 0) {
					ans = 0;
					break;
				}
			}
			j++;
		}
		return ans;
	}
}
/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