using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Введите число");

        var number = Convert.ToInt32(Console.ReadLine());

        if (isPrime(number)) Console.WriteLine("ПРОСТОЕ");

        else Console.WriteLine("Не простое");

    }

    static bool isPrime(int number)

    {

        int devisors = 0;

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

            if (number % i == 0)                        

            devisors++;   

        return devisors == 2;

    }

}