#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  string s;
  cin >> s;
  long long ans = 0, n = s.length(), i, j, k, x, sign;
  for (i = 0; i < n; i++) {
    if (s[i] == '+') {
      x = '+' - '0';
      i++;
      sign = 1;
    } else if (s[i] == '-') {
      x = '-' - '0';
      i++;
      sign = -1;
    } else {
      x = 0;
      sign = 1;
    }
    for (j = i; (j < n) && (s[j] != '+') && (s[j] != '-'); j++) {
      x = x * 10 + s[j] - '0';
    }
    ans += sign * x;
    i = j - 1;
  }
  cout << ans << "\n";
  return 0;
}
