#include <bits/stdc++.h>
using namespace std;
int main() {
  ios ::sync_with_stdio(0);
  cin.tie(0);
  string s;
  cin >> s;
  int flag = 1;
  int sum = 0, cur = 0;
  for (int i = 0; i < (int)s.size(); ++i) {
    if (s[i] == '-' || s[i] == '+') {
      sum += flag * cur;
      cur = 0;
      if (s[i] == '+') flag = 1;
      if (s[i] == '-') flag = -1;
    }
    ((cur *= 10) += (s[i] - '0'));
  }
  cout << sum + flag * cur;
}
