#include <bits/stdc++.h>
using namespace std;
int main() {
  char s[1003], ch;
  int ans = 0, nr = 0, ls = 0, i = 0;
  int sign = 1;
  cin.getline(s, 1000);
  ls = strlen(s);
  while (i < ls) {
    ch = s[i];
    if (ch == '-') {
      ans += nr * sign;
      sign = -1;
      nr = '-' - '0';
    } else if (ch == '+') {
      ans += nr * sign;
      sign = 1;
      nr = '+' - '0';
    } else {
      nr = nr * 10 + ch - '0';
    }
    i++;
  }
  ans += nr * sign;
  cout << ans;
}
