using System.Threading;

using System;

public class Program {

    public static int accountBalance = 50;

    public static Object accountBalanceLock = new Object();

    public static double creditScore = 1.0;

     static public void Main() 

    { 

        Thread add150 = new Thread(() => Add(150,0.3));

        Thread pay200 = new Thread(() => Pay(200,0.2));

        Thread pay50 = new Thread(() => Pay(50,0.05));

        Thread add300 = new Thread(() => Add(300,0.6));

        Thread add100 = new Thread(() => Add(100,0.2));

        Thread pay350 = new Thread(() => Pay(350,0.35));

        add150.Start();

        pay50.Start();

        pay200.Start();

        add300.Start();

        add100.Start();

        pay350.Start();

        add150.Join();

        pay50.Join();

        pay200.Join();

        add300.Join();

        add100.Join();

        pay350.Join();

        Console.WriteLine($"Account Balance is {accountBalance}");

​

     } 

    public static void Pay(int sum, double scoreModifier) 

    {  

​

        lock(accountBalanceLock){

            Console.WriteLine($"PAY  balance: {accountBalance}, paying {sum}, credit score bonus: {scoreModifier}");

            if(accountBalance < sum)

            {

                Console.WriteLine("Insufficient funds!");

            }

            else

            {

            accountBalance = accountBalance - sum;

            }

            Console.WriteLine($"PAY balance: {accountBalance}, credit score {creditScore}");

        }

            creditScore = creditScore + scoreModifier;      

    } 

​

    public static void Add(int sum, double scoreModifier)

    {

       lock(accountBalanceLock)

       {

               Console.WriteLine($"ADD  balance: {accountBalance}, adding {sum}, credit score bonus: {scoreModifier}");

​

            accountBalance = accountBalance + sum;  

               Console.WriteLine($"ADD balance: {accountBalance}, credit score {creditScore}");

​

       } 

       creditScore = creditScore + scoreModifier;

​

    }

} 

​