Letters Change Numbers

package com.company;

import java.util.*;

public class Main {

    public static void main(String[] args) {
        // write your code here
        Scanner scanner = new Scanner(System.in);
        String [] strings = scanner.nextLine().split("\\s+");

        double sum = 0;

        for (String string : strings) {
            char before = string.charAt(0);
            char after = string.charAt(string.length()-1);

            long number = Long.parseLong(string.substring(1, string.length() - 1));
            sum += calcCurrentValue(before, after, number);

        }
        System.out.printf("%.2f", sum);
    }
    private static double calcCurrentValue(char before, char after, long number){
        double value = 0;

        if (Character.isUpperCase(before)){
            value += (number * 1.00) / (before - 'A' +1) ;

        }else {
            value += number * (before - 'a' +1);

        }
        if (Character.isUpperCase(after)){
            value -= (after - 'A' +1);

        }else {
            value += (after - 'a' +1);

        }
        return value;
    }

}