Decoding

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

namespace Problem2
{
    class Decoding
    {
        static void Main(string[] args)
        {
            int salt = int.Parse(Console.ReadLine());
            double result = 0;
            var encodedNumbers = new List<double>();
            string text = Console.ReadLine();
            for (int i = 0; i < text.Length; i++)
            {
                if (text[i] == '@')
                {
                    break;
                }
                else if (char.IsLetter(text[i]))
                {
                    result = (int)text[i] * salt + 1000;
                    if (i % 2 == 0)
                    {
                        result /= 100.0;
                        Console.WriteLine("{0:F2}", result);
                    }
                    else
                    {
                        result *= 100;
                        Console.WriteLine(result);
                    }
                }
                else if (char.IsDigit(text[i]))
                {
                    result = (int)text[i] + salt + 500;
                    if (i % 2 == 0)
                    {
                        result /= 100.0;
                        Console.WriteLine("{0:F2}", result);
                    }
                    else
                    {
                        result *= 100;
                        Console.WriteLine(result);
                    }
                }
                else
                {
                    result = (int)text[i] - salt;
                    if (i % 2 == 0)
                    {
                        result /= 100.0;
                        Console.WriteLine("{0:F2}", result);
                    }
                    else
                    {
                        result *= 100;
                        Console.WriteLine(result);
                    }
                }


            }

        }
    }
}