using System;

​

public class Program

{

    public static void Main()

    {

        // ALejandro Campos

        int num, a = 0, p = 0;

        Console.WriteLine("Write as many numbers as you want, but once yopu type a zero you the program will stop and tell you how many prime numbers were written.");

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

        while (num != 0)

        {

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

            {

                if (num % i == 0)

                {

                    a++;

                }

            }

            if (a == 2)

            {

                p++;

            }

            a = 0;

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

        }

​

        Console.WriteLine("Prime numbers: " + p );

    }

}