#include <bits/stdc++.h>
using namespace std;
char s[1005];
long long ans = 0, x = 0, flag = 1;
int main() {
  cin >> s;
  int len = strlen(s);
  for (int i = 0; i < len; i++) {
    if (s[i] < '0' || s[i] > '9') {
      ans += x * flag;
      x = 0;
      flag = s[i] == '+' ? 1 : -1;
      x = x * 10 + s[i] - '0';
    } else
      x *= 10, x += s[i] - '0';
  }
  ans += x * flag;
  printf("%d", ans);
  return 0;
}
