#include <bits/stdc++.h>
using namespace std;
string s;
int l, c, x, f = 1;
inline void write(long long x) {
  if (x < 0) {
    putchar('-');
    x = -x;
  }
  if (x > 9) write(x / 10);
  putchar(x % 10 + '0');
  return;
}
signed main() {
  cin >> s;
  l = s.size();
  for (register int i = 0; i < l; ++i) {
    if (s[i] < '0' || s[i] > '9') {
      c += x * f;
      x = 0;
      if (s[i] == '+') f = 1;
      if (s[i] == '-') f = -1;
      x = x * 10 + (s[i] - '0');
    }
    if (s[i] >= '0' && s[i] <= '9') {
      x *= 10;
      x += (s[i] - '0');
    }
  }
  c += x * f;
  write(c);
  return 0;
}
