#include <bits/stdc++.h>
using namespace std;
int main(int argc, char *argv[]) {
  int ans = 0;
  char s[1000] = {'\0'};
  scanf("%d%s", &ans, s);
  for (int i = 0; s[i] != '\0';) {
    int num = s[i] - '0';
    int j = i + 1;
    for (; s[j] - '0' >= 0; j++) {
      num = 10 * num + s[j] - '0';
    }
    if (s[i] == '+') {
      ans += num;
    } else {
      ans -= num;
    }
    i = j;
  }
  cout << ans << endl;
  return 0;
}
