using System;


namespace exercise1assignment
{
    class Program
    {
        static void Main(string[] args)
        {

            {              
                Console.WriteLine("Hello, please type your name : ");
                string name = Console.ReadLine();

                while (string.IsNullOrEmpty(name) == true) //handling the exceptin if the value is null or empty
                {
                    Console.WriteLine("Please type your name in the right format : ");
                    name = Console.ReadLine();
                    Console.Clear();
                }
                int quantity = 0;
                bool isok = false;          
                while (isok == false)
                {
                    try
                    {
                        Console.WriteLine("Enter number of products : ");
                        quantity = int.Parse(Console.ReadLine());
                    }

                    catch { Console.WriteLine("Wrong format. Press any key..."); }
                    Console.ReadKey();
                    
                    {
                        if (quantity> 0)                        
                            isok = true;                       
                        else                       
                            isok = false;                                              
                    }
                    Console.Clear();
                }

                double price = 0; bool value = false;

                while(value== false)
                {
                    try
                    {
                        Console.WriteLine("Enter price for product : ");
                        price = Convert.ToDouble(Console.ReadLine());
                    }
                    catch { Console.WriteLine("Wrong format. Press any key..."); }
                    Console.ReadKey();
                   
                    {
                        if (price > 0)
                            value = true;
                        else
                            value = false;
                    }
                    Console.Clear();
                }

                
                
                price = quantity * price;
                Console.WriteLine("{0}, has to pay  {1}", name, price);
                Console.ReadKey();
            }
          
        }
    }
}
