#include <bits/stdc++.h>
using namespace std;
char a[100];
int len;
long long res = 0, cur = 0;
int sign = 1;
int main() {
  cin >> a;
  len = strlen(a);
  for (int i = 0; i < len; i++) {
    if (a[i] == '-' || a[i] == '+') {
      res += sign * cur;
      cur = 0;
    }
    if (a[i] == '-') sign = -1;
    if (a[i] == '+') sign = 1;
    cur = cur * 10 + a[i] - '0';
  }
  res += sign * cur;
  cout << res;
  return 0;
}
