#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
#define rep(i,l,r) for(int i=(l);i<(r);i++)
#define fcout cout << fixed << setprecision(10)
int main(){
    string s;
    cin>>s;
    int ans = 0,minus=1,reverse=1;
    while (s.size()) {
        if(s.front()=='+');
        else if(s.front()=='-')minus=-1;
        else if(s.front()=='('){
            reverse=minus;
            minus=1;
        }
        else if(s.front()==')')reverse=1;
        else{
            ans+=(s.front()-'0')*minus*reverse;
            minus=1;
        }
        s.erase(s.begin());
    }
    cout<<ans;
}