#include <bits/stdc++.h>
using namespace std;
inline long long read() {
  long long x = 0;
  bool f = false;
  char c = getchar();
  while (c < '0' || c > '9') {
    if (c == '-') f = true;
    c = getchar();
  }
  while (c >= '0' && c <= '9') {
    x = (x << 3) + (x << 1) + (c ^ '0');
    c = getchar();
  }
  return f ? -x : x;
}
inline void write(long long x) {
  if (x < 0) putchar('-'), x = -x;
  if (x > 9) write(x / 10);
  putchar(x % 10 + '0');
}
string s;
long long n, ans, x, y = 1;
signed main() {
  cin >> s;
  register long long len = s.length();
  for (register long long i = 0; i < len; ++i) {
    if (!isdigit(s[i])) {
      ans += x * y;
      x = 0;
      s[i] == '+' ? y = 1 : y = -1;
      x = x * 10 + s[i] - '0';
    }
    if (isdigit(s[i])) x = x * 10 + s[i] - '0';
  }
  ans += x * y;
  cout << ans;
  return 0;
}
