using System;

​

class Offers

{

    public int CheckNo(string No)

    {

       int result = 0;

        try

        {

             result = Int32.Parse(No);

        }

        catch (FormatException)

        {

            Console.WriteLine("Please enter a valid number");

        }

        return result;

    }

    public void CalculatePrice(int A, int B, int C, int D)

    {

        int Total = 0;

        int OfrTotal = 0;

        int UnitPrice = 0;

        if(A>3)

        {

            OfrTotal = (A/3)*130;

            UnitPrice = (A%3)*50;

            Total = Total+OfrTotal+UnitPrice;

        }

        else

        {

            Total = Total+(A*50);

        }

        if(B>2)

        {

            OfrTotal = (B/2)*45;

            UnitPrice = (B%2)*30;

            Total = Total+OfrTotal+UnitPrice;

        }

        else

        {

            Total = Total+(B*30);

        }

        if(C>0 && D>0)

        {

            if(C>D)

            {

                OfrTotal = 30*D;

                UnitPrice = (C-D)*20;

            }

            else if(D>C)

            {

                OfrTotal = 30*C;

                UnitPrice = (D-C)*15;

            }

            else

            {

             OfrTotal = 30*C;

             UnitPrice=0;

            }

            Total = Total+OfrTotal+UnitPrice;

        }

        else

        {

            Total = Total+(20*C)+(15*D);

        }

        Console.WriteLine("Total: "+Total);

    }

}

public class Program

{   

    public static void Main()

    {

        Console.WriteLine("Unit price for SKU IDs");

        Console.WriteLine("A    50"+"\n" +"B    30"+"\n" +"C    20"+"\n" +"D    15");

        Console.WriteLine("\n\n");

        Console.WriteLine("Active Promotions");

        Console.WriteLine("3 of A's for 130");

        Console.WriteLine("2 of B's for 45");

        Console.WriteLine("C & D for 30");

        Offers Ofr = new Offers();

        Console.WriteLine("\n\n");

        Console.WriteLine("Please enter no of units");

        Console.Write("A:");

        string A = Console.ReadLine();

        int AUnits= Ofr.CheckNo(A);

        Console.Write("B:");

        string B = Console.ReadLine();

        int BUnits= Ofr.CheckNo(B);

        Console.Write("C:");

        string C = Console.ReadLine();

        int CUnits= Ofr.CheckNo(C);

        Console.Write("D:");

        string D = Console.ReadLine();

        int DUnits= Ofr.CheckNo(D);

        Ofr.CalculatePrice(AUnits, BUnits, CUnits, DUnits);     

    }

}