#include <bits/stdc++.h>
using namespace std;
string s;
int get_int(string s) {
  int ans = 0;
  for (int i = 0; i < s.length(); i++) ans = ans * 10 + (s[i] - '0');
  return ans;
}
int main() {
  ios::sync_with_stdio(false);
  cin >> s;
  string temp = "";
  int ans = 0, sign = 1;
  for (int i = 0; i < s.length(); i++) {
    if (s[i] == '+') {
      ans += sign * get_int(temp);
      temp = "+";
      sign = 1;
    } else if (s[i] == '-') {
      ans += sign * get_int(temp);
      temp = "-";
      sign = -1;
    } else {
      temp += s[i];
    }
  }
  if (temp != "") {
    ans += sign * get_int(temp);
  }
  cout << ans << endl;
  return 0;
}
