package May_03_2017_Exam;


import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Stream;
import java.util.Scanner;

public class LetterExpression {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String input = in.nextLine();
        String[] numStr = input.split("[-]?[^0-9]+");
        Double[] numbers = new Double[numStr.length];
        for (int i = 0; i < numStr.length; i++)
        {
            numbers[i] = Double.parseDouble(numStr[i]);
        }
        String[]miPl = input.trim().split("([-]?[0-9]+)");
        miPl = Arrays.stream(miPl).filter(x -> !x.equals("")).toArray(String[]::new);
        change(miPl);
        Double sum = calculate(miPl, numbers);
        int sumInt = sum.intValue();
        System.out.println(sumInt);

    }
    private static String[] removeNull(String[] arr)
    {

        List<String> list = new ArrayList<String>();

        for(String s : arr) {
            if (!s.equals(""))
                list.add(s);

        }

        arr = list.toArray(new String[list.size()]);
        return arr;
    }
    private static Double calculate(String[] signs, Double[] nums)
    {
        Double sum = nums[0];
        for (int i = 1; i < nums.length; i++)
        {
            if (signs[i-1].equals("+"))
                sum += nums[i];
            else if(signs[i-1].equals("-"))
                sum -= nums[i];
        }
        return sum;
    }


    private static String[] change(String[] arr)
    {
        for (int i = 0; i< arr.length; i++)
        {
            if(arr[i].length() % 2 == 0)
                arr[i] = "+";
            else
                arr[i] = "-";
        }
        return arr;
    }
}