#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <array>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
using namespace std;

class Node{
public:
    char ope;
    string s;
    Node *left, *right;
    Node(){
        ope = '\0';
        left = right = NULL;
    }
    ~Node(){
        delete left;
        delete right;
    }
};

// 数式の構文木を作成する
class syntacticAnalysis
{
    vector<int> binaryPriority;       // 二項演算子の優先順位（数値が小さいほど優先順位が高い。-1ならば二項演算子ではない）
    vector<bool> binaryAssociativity; // 二項演算子の結合規則（trueならば左から右に結合）
    vector<bool> isUnaryOpe;          // 単項演算子
    stack<pair<Node*, bool> > stk;
    void deleteAllNodes()
    {
        while(!stk.empty()){
            delete stk.top().first;
            stk.pop();
        }
    }
    bool calc(int maxPriority)
    {
        if(!stk.top().second)
            return false;
        pair<Node*, bool> right = stk.top();
        stk.pop();
        while(stk.top().first != NULL){
            pair<Node*, bool> ope = stk.top();
            if(ope.second)
                break;
            stk.pop();
            if(binaryPriority[ope.first->ope] != -1 && stk.top().second){
                if(binaryPriority[ope.first->ope] > maxPriority ||
                        binaryPriority[ope.first->ope] == maxPriority && !binaryAssociativity[ope.first->ope]){
                    stk.push(ope);
                    break;
                }
                ope.first->right = right.first;
                ope.first->left = stk.top().first;
                ope.second = true;
                right = ope;
                stk.pop();
            }else if(isUnaryOpe[ope.first->ope]){
                ope.first->right = right.first;
                ope.second = true;
                right = ope;
            }else{
                stk.push(ope);
                break;
            }
        }
        bool ret = (stk.top().first == NULL);
        stk.push(right);
        return ret;
    }
public:
    // binaryOpe : 二項演算子（優先順位の高い順に並べる。secondは結合規則を表し、trueならば左から右に結合）
    // unaryOpe  : 単項演算子（前置演算子のみ対応）
    syntacticAnalysis(const vector<pair<string, bool> >& binaryOpe, const string& unaryOpe)
    {
        binaryPriority.assign(128, -1);
        binaryAssociativity.resize(128);
        isUnaryOpe.assign(128, false);
        for(unsigned i=0; i<binaryOpe.size(); ++i){
            for(unsigned j=0; j<binaryOpe[i].first.size(); ++j){
                binaryPriority[binaryOpe[i].first[j]] = i;
                binaryAssociativity[binaryOpe[i].first[j]] = binaryOpe[i].second;
            }
        }
        for(unsigned i=0; i<unaryOpe.size(); ++i)
            isUnaryOpe[unaryOpe[i]] = true;
    }
    Node* makeTree(const string& s)
    {
        int n = s.size();
        int i = 0;
        stk.push(make_pair((Node*)NULL, false));
        while(i < n){
            if(s[i] == '('){
                stk.push(make_pair((Node*)NULL, false));
                ++ i;
            }else if(s[i] == ')'){
                if(!calc(INT_MAX) || stk.size() == 2){
                    deleteAllNodes();
                    return NULL;
                }
                pair<Node*, bool> node = stk.top();
                stk.pop();
                stk.pop();
                stk.push(node);
                ++ i;
            }else if(binaryPriority[s[i]] != -1 || isUnaryOpe[s[i]]){
                calc(binaryPriority[s[i]]);
                Node* node = new Node;
                node->ope = s[i];
                stk.push(make_pair(node, false));
                ++ i;
            }else{
                Node* node = new Node;
                while(i < n && s[i] != '(' && s[i] != ')' && binaryPriority[s[i]] == -1 && !isUnaryOpe[s[i]]){
                    node->s += s[i];
                    ++ i;
                }
                stk.push(make_pair(node, true));
            }
        }

        if(!calc(INT_MAX) || stk.size() != 2){
            deleteAllNodes();
            return NULL;
        }else{
            Node* ret = stk.top().first;
            stk.pop();
            stk.pop();
            return ret;
        }
    }
};

int solve(const Node* node)
{
    if(node->ope == '+')
        return solve(node->left) + solve(node->right);
    else if(node->ope == '-')
        return solve(node->left) - solve(node->right);
    else
        return stoi(node->s);
}

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

    syntacticAnalysis sa({make_pair("+-", true)}, "");
    Node* node = sa.makeTree(s);
    cout << solve(node) << endl;
    delete node;

    return 0;
}