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


class LettersChangeNumbers
{
    static void Main()
    {
        string[] input = Console.ReadLine().Split().ToArray();
        decimal sum = 0;

        for (int i = 0; i < input.Length; i++)
        {
            string arrElement = input[i].ToString();

            if ((arrElement[0] >= 65 && arrElement[0] <= 90) && (arrElement[arrElement.Length - 1] >= 65 && arrElement[arrElement.Length - 1] <= 90))
            {
                decimal firstUpper = arrElement[0] - 64;
                decimal lastUpper = arrElement[arrElement.Length - 1] - 64;
                string number = arrElement.Substring(1, arrElement.Length - 2);

                decimal dividend = decimal.Parse(number);
                sum = (dividend / firstUpper) - lastUpper;
            }

            if ((arrElement[0] >= 65 && arrElement[0] <= 90) && (arrElement[arrElement.Length - 1] >= 97 && arrElement[arrElement.Length - 1] <= 122))
            {
                decimal firstUpper = arrElement[0] - 64;
                decimal lastLower = arrElement[arrElement.Length - 1] - 96;
                string number = arrElement.Substring(1, arrElement.Length - 2);

                decimal dividend = decimal.Parse(number);
                sum = sum + (dividend / firstUpper) + lastLower;
            }

            if ((arrElement[0] >= 97 && arrElement[0] <= 122) && (arrElement[arrElement.Length - 1] >= 65 && arrElement[arrElement.Length - 1] <= 90))
            {
                decimal firstLower = arrElement[0] - 96;
                decimal lastUpper = arrElement[arrElement.Length - 1] - 64;
                string number = arrElement.Substring(1, arrElement.Length - 2);

                decimal dividend = decimal.Parse(number);
                sum = sum + (dividend * firstLower) - lastUpper;
            }

            if ((arrElement[0] >= 97 && arrElement[0] <= 122) && (arrElement[arrElement.Length - 1] >= 97 && arrElement[arrElement.Length - 1] <= 122))
            {
                decimal firstLower = arrElement[0] - 96;
                decimal lastLower = arrElement[arrElement.Length - 1] - 96;
                string number = arrElement.Substring(1, arrElement.Length - 2);

                decimal dividend = decimal.Parse(number);
                sum = sum + (dividend * firstLower) + lastLower;
            }
        }
        Console.WriteLine("{0:F2}",sum);
    }
}