#include <bits/stdc++.h>
using namespace std;
char str[100];
int ans, len, tmp;
bool f = 1;
int main() {
  scanf("%s", str);
  len = strlen(str);
  for (int i = 0; i < len; ++i) {
    if (str[i] >= '0' && str[i] <= '9')
      tmp = tmp * 10 + str[i] - '0';
    else {
      if (f)
        ans += tmp;
      else
        ans -= tmp;
      if (str[i] == '+')
        f = 1;
      else
        f = 0;
      tmp = 0;
      tmp = tmp * 10 + str[i] - '0';
    }
  }
  if (f)
    ans += tmp;
  else
    ans -= tmp;
  printf("%d\n", ans);
  return 0;
}
