#include <bits/stdc++.h>
using namespace std;
template <class A>
void addlog(A a) {
  cerr << a << endl;
}
template <class A, class... B>
void addlog(A a, B... b) {
  cerr << a << ' ';
  addlog(b...);
}
char c;
int sum = 0, cur = 0;
int sign = +1;
int main() {
  while (cin >> c) {
    if (c == '+' || c == '-') {
      sum += cur;
      cur = 0;
      if (c == '+') sign = +1;
      if (c == '-') sign = -1;
    }
    cur = 10 * cur + sign * (c - '0');
  }
  cout << sum + cur << endl;
  return 0;
}
