import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);
      int X = sc.nextInt();
      int prime = X;
      int mid = prime/2;
      boolean flag = false;
      while (true){
        for(int i = 2; i <= mid; ++i){
        	if(prime % i == 0)
            {
              flag = true;
              break;
            }
        }
        if (!flag){
          break;
        }
        else
          flag = false;
          prime++;
      }
      System.out.println(prime);
    }
}
/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