#include <bits/stdc++.h>
using namespace std;

#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define repi(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define all(x) (x).begin(),(x).end()
#define foreach(u,v) for(auto (u) : (v))
#define pb push_back
#define mp make_pair
#define mt make_tuple

typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<ll, ll> pll;
typedef vector<ll> vl;

const int inf = 1e9;
const ll linf = 1LL<<60;
const ll mod = 1e9 + 7;
const double eps = 1e-9;

/*
*/

int main()
{
  string s;
  cin >> s;
  int n = s.size();

  int ans = 0, op1 = 1, op2 = 1;
  rep(i, n){
    if('0' <= s[i] and s[i] <= '9'){
      ans += (s[i]-'0')*op1*op2; 
    }else if(s[i] == '('){
      op2 = op1;
      op1 = 1;
    }else if(s[i] == ')'){
      op2 = 1;
    }else if(s[i] == '+'){
      op1 = 1;
    }else if(s[i] == '-'){
      op1 = -1;
    }
  }

  cout << ans << endl;

  return 0;
}