#include <bits/stdc++.h>
using namespace std;
template <typename _T>
inline void _DBG(const char *s, _T x) {
  cerr << s << " = " << x << "\n";
}
template <typename _T, typename... args>
void _DBG(const char *s, _T x, args... a) {
  while (*s != ',') cerr << *s++;
  cerr << " = " << x << ',';
  _DBG(s + 1, a...);
}
int main() {
  string s;
  cin >> s;
  int sgn = 1, tmp = 0, ans = 0;
  for (int i = 0; i < (int)(s).size(); i++) {
    if (s[i] == '+' || s[i] == '-') ans += tmp * sgn, tmp = 0;
    if (s[i] == '+') sgn = 1;
    if (s[i] == '-') sgn = -1;
    tmp = 10 * tmp + (s[i] - '0');
  }
  ans += tmp * sgn;
  cout << ans << "\n";
  return 0;
}
