using System;

public class Program

{ public static void songuyento(int n)

        {

            int t;

            t = 1;

            for (int i = 1; i <= n; i++)

            {

               if (n%i == 0) {

                    t = t * i;

                }

            }

            if (t == n)

            {

                Console.WriteLine("La so nguyen to");

            }

            else

            {

                Console.WriteLine("Khong phai so nguyen to");

            }

        }

    public static void Main()

    {

            Console.WriteLine("nhap n:");

            int n = int.Parse(Console.ReadLine());

            songuyento(n);

    }

}