#include <bits/stdc++.h>
using namespace std;
string s;
int k, sum, ans;
int main() {
  cin >> s;
  for (int i = 0; i < s.length(); i++) {
    if (s[i] >= '0' && s[i] <= '9') {
      sum *= 10;
      sum += s[i] - '0';
      k = i;
    } else {
      break;
    }
  }
  ans = sum;
  sum = 0;
  for (int i = k + 1; i < s.length(); i++) {
    if (s[i] >= '0' && s[i] <= '9') {
      if (s[i - 1] == '-') {
        sum = '-' - '0';
        for (int j = i; j < s.length(); j++) {
          if (s[j] >= '0' && s[j] <= '9') {
            sum *= 10;
            sum += s[j] - '0';
            i = j;
          } else {
            break;
          }
        }
        ans -= sum;
        sum = 0;
      }
      if (s[i - 1] == '+') {
        sum = '+' - '0';
        for (int j = i; j < s.length(); j++) {
          if (s[j] >= '0' && s[j] <= '9') {
            sum *= 10;
            sum += s[j] - '0';
            i = j;
          } else {
            break;
          }
        }
        ans += sum;
        sum = 0;
      }
    }
  }
  cout << ans << endl;
  return 0;
}
