Tрета

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

namespace Exam
{
    class Program
    {
        static void Main(string[] args)
        {
            string inputCurrency = Console.ReadLine();
            double enteredMoney = Double.Parse(Console.ReadLine());
            double xrp = 0.22;
            double btc = 6400;
            double eth = 250;
            bool purchased = true;
            if (inputCurrency != "ETH" && inputCurrency != "XRP" && inputCurrency != "BTC")
            {
                Console.WriteLine($"EUR to {inputCurrency} is not supported!");
                return;
            }
            if (enteredMoney > 1000)
            {
                enteredMoney *= 1.1;
            }
            double purchasedValue = 0;
            if (inputCurrency == "BTC")
            {
                purchasedValue = enteredMoney / btc;
                if (purchasedValue < 0.001)
                {
                    Console.WriteLine("Insufficient funds");
                    purchased = false;
                }
                if (purchasedValue > 10)
                {
                    purchasedValue *= 1.02;
                }
            }
            if (inputCurrency == "ETH")
            {
                purchasedValue = enteredMoney / eth;
                if (purchasedValue < 0.0099)
                {
                    Console.WriteLine("Insufficient funds");
                    purchased = false;
                }
            }
            if (inputCurrency == "XRP")
            {
                purchasedValue = enteredMoney / xrp;
                if (purchasedValue < 80)
                {
                    Console.WriteLine("Insufficient funds");
                    purchased = false;
                }
                if (purchasedValue > 1000 && purchasedValue < 2500)
                {
                    purchasedValue *= 1.05;
                }
                if (purchasedValue >= 2500)
                {
                    purchasedValue *= 1.1;
                }
            }
            if (purchased)
            {
                Console.WriteLine($"Successfully purchased {purchasedValue:f3} {inputCurrency}");
            }
        }
    }
}