import java.util.*;
    public class Main {
    	public static void main(String[] args){
    		Scanner sc = new Scanner(System.in);
    		int x = sc.nextInt();
            for(int i=2;i<=Math.sqrt(x);i++){
              if(x%i==0){
                x++;
                i=1;
              }
            }

    		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