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