#include <bits/stdc++.h>
using namespace std;
long long n, x, ans, b;
string a;
int main() {
  cin >> a;
  n = a.size();
  b = 1;
  for (int i = 0; i < n; i++) {
    if (a[i] == '-') {
      ans += b * x;
      b = -1;
      x = 0;
    } else if (a[i] == '+') {
      ans += b * x;
      b = 1;
      x = 0;
    }
    x *= 10;
    x += (a[i] - '0');
  }
  ans += b * x;
  cout << ans << endl;
  return 0;
}
