import java.util.Scanner;
 
public class Main
{
  public static void main(String args[])
  {
    Scanner std = new Scanner(System.in);
    int n = std.nextInt();
    
    while(true)
    {
      int count = 0;
        for(int i = 2; i < n; i++)
    	{
      		if(n % i == 0)
      		{
				count++;
      		}
    	}
      if(count == 0)
      {
        System.out.println(n);
        System.exit(0);
      }
      n++;
    }
  }
}
/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