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=X; ; i++) {
      boolean b = false;
      for (int j=2; j<=X/2; j++) {
        if (i%j == 0) {
          b = true;
          break;
        }
      }
      if (!b) {
        System.out.println(i);
        break;
      }
    }
  }
}
//
/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