Първа

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Passwords
{
    class Program
    {
        static void Main(string[] args)
        {
            double startingMoney = double.Parse(Console.ReadLine());
            double bitcoinPrice = double.Parse(Console.ReadLine());
            int satoshi = int.Parse(Console.ReadLine());
            double boughtBitcoin = startingMoney / bitcoinPrice;
            double tax = boughtBitcoin * (satoshi * 1024) / 100000000;
            boughtBitcoin -= tax;
            double myProfit = boughtBitcoin * 0.1;
            double stephansMoney = boughtBitcoin - myProfit;
            Console.WriteLine($"Total bitcoin after expenses: {stephansMoney:f5} BTC");
            Console.WriteLine($"Tax payed: {(tax * bitcoinPrice):f2} USD");
            Console.WriteLine($"Programmer`s payment: {myProfit:f5} BTC");
        }
    }
}