#include <bits/stdc++.h>
using namespace std;
char a[100001];
int n, f = 1, x, ans;
int main() {
  cin >> a;
  n = strlen(a);
  for (int i = 0; i < n; i++) {
    if (a[i] < '0' || a[i] > '9') {
      ans += x * f;
      x = 0;
      if (a[i] == '-') f = -1;
      if (a[i] == '+') f = 1;
      x = x * 10 + a[i] - '0';
    }
    if (a[i] >= '0' && a[i] <= '9') {
      x *= 10;
      x += a[i] - '0';
    }
  }
  ans += x * f;
  cout << ans;
  return 0;
}
