import java.util.*;

class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    int X = scan.nextInt();
    
    while(true){
      
      int count = 0;
      for (int i = 2; i < (X-1); i++){
        if (X % i == 0){
          count++;
          break;
        }
      }
      
      if (count == 0){
        System.out.println(X);
        return;
      }
      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