#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)
#define FOR(i,b,e) for (int i=(int)(b); i<(int)(e); i++)
#define ALL(x) (x).begin(), (x).end()

const double PI = acos(-1);

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  string s;
  cin >> s;

  int ret = 0;
  int x = 1;
  int y = 1;
  for (char c: s) {
    if (c == '(') {
      x = y;
      y = 1;
    }
    else if (c == ')')
      x = 1;
    else if (c == '+')
      y = 1;
    else if (c == '-')
      y = -1;
    else
      ret += x * y * (c - '0');
  }
  cout << ret << endl;
  
  return 0;
}