#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline void read(T &x) {
  char c;
  bool nega = 0;
  while ((!isdigit(c = getchar())) && (c != '-'))
    ;
  if (c == '-') {
    nega = 1;
    c = getchar();
  }
  x = c - 48;
  while (isdigit(c = getchar())) x = x * 10 + c - 48;
  if (nega) x = -x;
}
template <typename T>
inline void writep(T x) {
  if (x > 9) writep(x / 10);
  putchar(x % 10 + 48);
}
template <typename T>
inline void write(T x) {
  if (x < 0) {
    putchar('-');
    x = -x;
  }
  writep(x);
  putchar(' ');
}
template <typename T>
inline void writeln(T x) {
  write(x);
  putchar('\n');
}
template <typename T>
inline void Min(T &a, T b) {
  if (a > b) a = b;
}
template <typename T>
inline void Max(T &a, T b) {
  if (a < b) a = b;
}
int main() {
  ios_base::sync_with_stdio(NULL);
  cin.tie(NULL);
  cout.tie(NULL);
  int x = 0;
  bool y = 1;
  int ans = 0;
  char xx;
  while (cin >> xx) {
    if (xx == '+' || xx == '-') {
      if (y)
        ans += x;
      else
        ans -= x;
      x = 0;
      y = (xx == '+');
    }
    x = x * 10 + (xx - '0');
  }
  if (y)
    ans += x;
  else
    ans -= x;
  cout << ans;
}
