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