#include <bits/stdc++.h>
using namespace std;
const int N = 1e4 + 10;
char a[N];
long long s, r, g = 1;
int main() {
  cin >> a;
  for (int i = 0; i < strlen(a); i++) {
    if (a[i] == '-' || a[i] == '+') {
      s += g * r;
      r = 0;
      switch (a[i]) {
        case '-': {
          g = -1;
          break;
        }
        case '+': {
          g = 1;
          break;
        }
      }
    }
    r = r * 10 + a[i] - '0';
  }
  s += g * r;
  cout << s;
  return 0;
}
