#include <bits/stdc++.h>
using namespace std;
const int mod = (int)1e9 + 7;
const int N = (int)2e5 + 123;
const long long inf = 3e18 + 1;
const double pi = acos(-1.0);
const double eps = 1e-9;
const int dx[] = {0, 0, 1, 0, -1};
const int dy[] = {0, 1, 0, -1, 0};
string s;
int ans;
inline void boost() {
  ios_base ::sync_with_stdio(NULL);
  cin.tie(NULL), cout.tie(NULL);
}
inline void Solve() {
  boost();
  cin >> s;
  int n = s.size();
  int id = 0;
  int ans = 0;
  while (id < n && isdigit(s[id])) {
    ans *= 10, ans += s[id] - '0';
    id++;
  }
  while (id < n) {
    char p = s[id];
    int y = s[id] - '0';
    id++;
    while (isdigit(s[id]) && id < n) y *= 10, y += s[id] - '0', id++;
    if (p == '+')
      ans += y;
    else
      ans -= y;
  }
  cout << ans;
}
int main() {
  int tt = 1;
  while (tt--) {
    Solve();
  }
  return 0;
}
