C# Csharp

    static void Main(String[] args) 
    {
        int row = int.TryParse(Console.ReadLine(), out int inputRow) ? inputRow : 0;

        while (row > 0)
        {
            int.TryParse(Console.ReadLine(), out int rec);

            if (rec > 1)
            {
                bool isPrime = true;

                // Optimized primality test: check divisors only up to the square root
                for (int i = 2; i * i <= rec; i++)
                {
                    if (rec % i == 0)
                    {
                        isPrime = false;
                        break;
                    }
                }

                string result = isPrime ? "Prime" : "Not prime";
                Console.WriteLine(result);
            }
            else
            {
                Console.WriteLine("Not prime");
            }

            row--;
        }
    }