#include <bits/stdc++.h>
using namespace std;
int main(int argc, char *argv[]) {
  int res = 0;
  string s;
  cin >> s;
  for (int i = 0, cur = 0, f = 1;; i++) {
    if (s[i] == '+' || s[i] == '-' || !s[i]) {
      res += cur * f;
      if (!s[i]) break;
      f = s[i] == '-' ? -1 : 1;
      cur = s[i] - '0';
    } else
      cur = (cur << 3) + (cur << 1) + s[i] - '0';
  }
  cout << res << endl;
  return 0;
}
