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


namespace Letters_Change_Numbers
{
    class Program
    {
      static void Main(string[] args)
        {
            string[] input =Console.ReadLine()
              .Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
            StringBuilder partition = new StringBuilder();
            double finalResult = 0;
            for (int i = 0; i < input.Length; i++)
            {
                partition.Append(input[i]);
                var firstL = partition[0];
                var secondR = partition[partition.Length - 1];
                double midle = double.Parse(getMatches(input[i]));
                double forEachArr = getMathResult(firstL, secondR, midle);
                finalResult += forEachArr;

                partition.Clear();
            }
            Console.WriteLine($"{finalResult:f2}");

        }

        static string getMatches(string n) {
        string patern = @"\d+";
        Regex regex = new Regex(patern);
        Match match = regex.Match(n);
        string midle = "";
            if (match.Success)
            {
                midle = match.Value;
            }
            return
            (midle);
        }

        static double getMathResult(char first, char second, double midle)
        {
            double sum = 0;
            if (first >= 65 && first<= 90)
            {
                sum = midle / (first - 64);

            }
            else if (first>=95 && first<=122)
            {
                sum = midle * (first - 96);
            }
            if (second >= 95 && second <= 122)
            {
                sum +=(second - 96);
            }
            if (second >= 65 && second <= 90)
            {
                sum -=(second - 64);
            }

            return
            (sum);
        }


    }
}