#include <bits/stdc++.h>
using namespace std;
int main() {
  char s[10010];
  cin >> s;
  int len = strlen(s), ans = 0, c = 0, t = 1;
  for (int i = 0; i < len; i++) {
    if (s[i] == '+' || s[i] == '-') {
      ans += c * t;
      c = 0;
    }
    if (s[i] == '+') {
      t = 1;
    }
    if (s[i] == '-') t = -1;
    c = c * 10 + s[i] - '0';
  }
  cout << ans + t * c << endl;
}
