#include <bits/stdc++.h>
using namespace std;
inline long long sqr(long long x) { return x * x; }
mt19937 Random((int)time(0));
inline long long rnd(long long x) { return Random() % x; }
const long long INF = (long long)1e9 + 2018;
const long long MOD = (long long)1e9 + 7;
const long double PI = acos(-1.0);
void $main() {
  string s;
  cin >> s;
  s += "+";
  long long res = 0, cur = 0, p = 1;
  for (char c : s) {
    if (c == '+' || c == '-') {
      res += p * cur;
      cur = 0;
    }
    if (c == '+') {
      p = 1;
    }
    if (c == '-') {
      p = -1;
    }
    cur *= 10ll;
    cur += c - '0';
  }
  cout << res;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cout.setf(ios_base::fixed, ios_base::floatfield);
  cout.precision(10);
  $main();
}
