#include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <math.h>
#include <cmath>
#include <limits.h>
#include <map>
#include <unordered_map>
#include <set>
#include <queue>
#include <algorithm>
#include <functional>
#include <stdio.h>
using namespace std;

long long MOD = 1000000007;

int main() {
    string S;
    cin >> S;

    int ans = 0;
    bool b1 = true;
    bool b2 = true;
    for ( int i = 0; i < S.length(); i++ ) {
        if ( isdigit(S[i]) ) {
            int a = S[i] - '0';
            ans += b1 == b2 ? a: -a;
        }
        else {
            if ( S[i] == '+' || S[i] == '-' ) {
                b1 = S[i] == '+';
            }
            else if ( S[i] == ')' ) {
                b1 = b2 = true;
            }
            else if ( S[i] == '(' ) {
                b2 = b1;
                b1 = true;
            }
            
        }
    }

    cout << ans << endl;

    return 0;
}