using System;
using System.Collections.Generic;
using System.Linq;

namespace _8._LettersChangeNumbers
{
    class LettersChangeNumbers
    {
        static void Main()
        {
            string input = Console.ReadLine();

            string[] splitedInput = input
                .Split(new char[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries);

            double totalSum = 0;

            for (int i = 0; i < splitedInput.Length; i++)
            {
                //char firstLetter = splitedInput[i][0];
                string currentInput = splitedInput[i];
                char firstLetter = currentInput[0];
                char lastLetter = currentInput[currentInput.Length - 1];

                double digit = double.Parse(currentInput.Substring(1, currentInput.Length - 2));

                if (char.IsUpper(firstLetter))
                {
                    digit /= firstLetter - 'A' + 1;
                }

                else
                {
                    digit *= firstLetter - 'a' + 1;
                }

                if (char.IsUpper(lastLetter))
                {
                    digit -= lastLetter - 'A' + 1;
                }

                else
                {
                    digit += lastLetter - 'a' + 1;
                }

                totalSum += digit;
            }

            Console.WriteLine(totalSum.ToString("f2"));
        }
    }
}