Prime numbers in given range (without method)

using System;

namespace _7._Prime_Numbers_in_Given_Range
{
    class Program
    {
        static void Main(string[] args)
        {
            long num1 = long.Parse(Console.ReadLine());
            long num2 = long.Parse(Console.ReadLine());

            if (num1 < 0 || num2 < 0)
            {
                num1 = 2;
            }
            if (num1 == 0 || num1 == 1)
            {
                num1 = 2;
            }
            if (num1 > num2)
            {
                Console.WriteLine("(empty list)");
            }


            for (long i = num1; i < num2; i++)
            {
                bool firstPrime = true;
                bool prime = true;

                if (i > 1)
                {
                    for (int j = 2; j < i; j++)
                    {
                        if (i % j == 0)
                        {
                            prime = false;

                            break;
                        }
                    }
                        if (prime == true && firstPrime == true)
                        {
                            Console.Write(i);
                            firstPrime = false;
                        }
                        else if (prime)
                        {
                            Console.Write(", ");
                            Console.Write($"{i} ");
                        }
                }
            }
            Console.WriteLine();
        }
    }
}