using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;

class LettersChangeNumbers
{
    static void Main()
    {
        string input = Console.ReadLine();
        string[] text = input.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
        List<string> textList = new List<string>();
        List<int> onlyNumbers = new List<int>();

        for(int i = 0; i < text.Length; i++)
        {
            textList.Add(text[i]);
        }


        string pattern = @"[0-9]+";
        Regex rgx = new Regex(pattern);
        for (int i = 0; i < textList.Count; i++)
        {
            Match mth = rgx.Match(textList[i]);
            string a = Convert.ToString(mth.Groups[0]);
            int number = int.Parse(a);
            onlyNumbers.Add(number);
        }

        double sum = 0;
        double sum1 = 0;

        for (int i = 0; i < text.Length; i++)
        {
                if (char.IsUpper(text[i][0]))
                {
                    double convert = (double)Convert.ToChar(text[i][0]);
                    sum1 = onlyNumbers[i] / (convert - 64.0);
                }
                else
                {
                    double convert = (double)Convert.ToChar(text[i][0]);
                    sum1 = onlyNumbers[i] * (convert - 96.0);
                }
                if (char.IsUpper(text[i][text[i].Length - 1]))
                {
                    double convert = (double)Convert.ToChar(text[i][text[i].Length - 1]);
                    sum += sum1 - (convert - 64.0);
                }
                else
                {
                    double convert = (double)Convert.ToChar(text[i][text[i].Length - 1]);
                    sum += sum1 + (convert - 96.0);
                }
        }

        Console.WriteLine("{0:F2}", sum);
    }
}