#define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define MT make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
#define RT return
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;

using Operators = array<int, 256>;
vector<pair<int, int>> shuntingYard(const string &s, Operators operators) {
    stack<int> stk;
    vector<pair<int, int>> re;

    for (int i = 0; i < sz(s);) {
        int nex = i + 1;
        if (s[i] == '(') {
            stk.push(i);
        } else if (s[i] == ')') {
            while (true) {
                int j = stk.top();
                stk.pop();
                if (s[j] == '(') {
                    break;
                } else {
                    re.emplace_back(j, j + 1);
                }
            }
        } else if (operators[s[i]] > 0) {
            while (!stk.empty() && operators[s[stk.top()]] >= operators[s[i]]) {
                int j = stk.top();
                stk.pop();
                re.emplace_back(j, j + 1);
            }
            stk.push(i);
        } else {
            while (nex < (int)s.size() && s[nex] != '(' && s[nex] != ')' && !operators[s[nex]]) {
                nex++;
            }
            re.emplace_back(i, nex);
        }
        i = nex;
    }

    while (!stk.empty()) {
        int i = stk.top();
        stk.pop();
        re.emplace_back(i, i + 1);
    }

    return re;
}

Operators ops;

void solve() {
    ops['+'] = ops['-'] = 1;
    string S;
    cin >> S;
    vector<pii> segs = shuntingYard(S, ops);

    stack<int> stk;
    each(p, segs) {
        char c = S[p.first];
        if (isdigit(c)) {
            stk.push(c - '0');
        } else {
            int y = stk.top(); stk.pop();
            int x = stk.top(); stk.pop();
            if (c == '+')stk.push(x + y);
            else stk.push(x - y);
        }
    }
    cout << stk.top() << endl;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout << fixed << setprecision(15);
	solve();
	return 0;
}