import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        char[] arr = br.readLine().toCharArray();
        ArrayDeque<Integer> deqInt = new ArrayDeque<>();
        ArrayDeque<Boolean> deqBool = new ArrayDeque<>();
        int base = 0;
        boolean isPlus = true;
        for (char c : arr) {
            if (c == '+') {
                isPlus = true;
            } else if (c == '-') {
                isPlus = false;
            } else if (c == '(') {
                deqInt.push(base);
                deqBool.push(isPlus);
                base = 0;
                isPlus = true;
            } else if (c == ')') {
                int x = deqInt.pop();
                isPlus = deqBool.pop();
                if (isPlus) {
                    base = x + base;
                } else {
                    base = x - base;
                }
            } else {
                if (isPlus) {
                    base += c - '0';
                } else {
                    base -= c - '0';
                }
            }
        }
        System.out.println(base);
    }
}