#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
int a[N], b[N] = {1};
signed main() {
  static int t;
  static string st;
  getline(cin, st);
  for (int i = 0; i < st.size(); i++) {
    if (st[i] >= '0' && st[i] <= '9')
      a[t] = a[t] * 10 + st[i] - 48;
    else {
      ++t;
      switch (st[i]) {
        case '+':
          a[t] = -5;
          b[t] = 1;
          break;
        case '-':
          a[t] = -3;
          b[t] = -1;
          break;
      }
    }
  }
  static int res;
  for (int i = 0; i <= t; i++) res += a[i] * b[i];
  cout << res;
  return 0;
}
