#include <bits/stdc++.h>
using namespace std;
int main() {
  string a;
  cin >> a;
  int sign = 1, now = 0, sum = 0;
  for (int i = 0; i < a.length(); i++) {
    if (a[i] == '+' || a[i] == '-') {
      sum += now * sign;
      if (a[i] == '+')
        sign = 1;
      else
        sign = -1;
      now = 0;
      now += a[i] - '0';
    } else {
      now *= 10;
      now += a[i] - '0';
    }
  }
  sum += sign * now;
  cout << sum << endl;
  return 0;
}
