import java.util.ArrayList;
import java.util.Scanner;

public class LettersChangeNumbers {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		String[] inputSplitted = sc.nextLine().split("\\s+");

		double firstTempResult = 1;
		double secondTempResult = 0;
		double finalResult;// = 0;

		ArrayList<String> inputSplittedAsArray = new ArrayList<String>();

		for (int i = 0; i < inputSplitted.length; i++) {
			inputSplittedAsArray.add(inputSplitted[i]);
		}

		firstTempResult = calculateTempInt(inputSplittedAsArray.get(0));

		for (int i = 1; i < inputSplittedAsArray.size(); i++) {
				while (i < inputSplittedAsArray.size() - 1) {
					firstTempResult = sumTempResults(firstTempResult, calculateTempInt(inputSplittedAsArray.get(i)));
					i = i+1;
				}

				secondTempResult = calculateTempInt(inputSplitted[inputSplittedAsArray.size() - 1]);
		}

		if (inputSplitted.length < 2) {
			finalResult = firstTempResult;
		}
		else {
			finalResult = sumTempResults(firstTempResult, secondTempResult);
		}

		System.out.printf("%.2f", finalResult);

	}

	public static double sumTempResults(double firstTempResult, double secondTempResult){
		double sum = firstTempResult + secondTempResult;
		return sum;
	}
	public static double calculateTempInt(String theString){
		int tempInt = extractIntFromString(theString);
		double tempResult = 1;
		if (checkUpperCase(theString.charAt(0))) {

			tempResult = (double)tempInt / getPositionInAlphabetOfChar(theString.charAt(0));
		}
		else if (checkLowerCase(theString.charAt(0))) {
			tempResult = (double)tempInt * getPositionInAlphabetOfChar(theString.charAt(0));
		}

		if (checkUpperCase(theString.charAt(theString.length() - 1))) {
			tempResult = (double)tempResult - getPositionInAlphabetOfChar(theString.charAt(theString.length() - 1));
		}
		else if (checkLowerCase(theString.charAt(theString.length() - 1))) {
			tempResult = (double)tempResult + getPositionInAlphabetOfChar(theString.charAt(theString.length() - 1));
		}

		return tempResult;
	}

	private static int extractIntFromString(String theString){

        String theIntAsString = theString.substring(1, theString.length() - 1);
        int theInt = Integer.parseInt(theIntAsString);
        return theInt;
	}

	public static int getPositionInAlphabetOfChar(char theChar){

		int asciiResult = (int)theChar;

		if (checkUpperCase(theChar)) {
			asciiResult = asciiResult - 64;
		}
		if (checkLowerCase(theChar)) {
			asciiResult = asciiResult - 96;
		}
        return asciiResult;
	}

	public static boolean checkUpperCase(char theChar){
		boolean result = Character.isUpperCase(theChar);
		return result;

	}

	public static boolean checkLowerCase(char theChar){
		boolean result = Character.isLowerCase(theChar);
		return result;

	}

}