using System;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        var startBalance = 100.0;

​

        int[] attemptedWithdrawals = {20, 10, 40, 50, 10, 70, 30};

        var endBalance = attemptedWithdrawals.Aggregate(startBalance, (balance, nextWithdrawal) => nextWithdrawal <= balance ? balance - nextWithdrawal : balance);

        Console.WriteLine("Ending balance: {0}", endBalance);

    }

}