#include <bits/stdc++.h>
using namespace std;
long long mod = 1000000007;
long long mod2 = 998244353;
long long mod3 = 1000003;
long long mod4 = 998244853;
long long inf = 1000000000000000000;
double pi = acos(-1.0);
int dh[4] = {1, -1, 0, 0};
int dw[4] = {0, 0, 1, -1};
int ddh[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
int ddw[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
long long lmax(long long a, long long b) {
  if (a < b)
    return b;
  else
    return a;
}
long long lmin(long long a, long long b) {
  if (a < b)
    return a;
  else
    return b;
}
long long gcd(long long a, long long b) {
  if (a < b) swap(a, b);
  if (b == 0) return a;
  if (a % b == 0) return b;
  return gcd(b, a % b);
}
long long Pow(long long n, long long k) {
  long long ret = 1;
  long long now = n;
  while (k > 0) {
    if (k & 1) ret *= now;
    now *= now;
    k /= 2;
  }
  return ret;
}
long long beki(long long n, long long k, long long md) {
  long long ret = 1;
  long long now = n;
  while (k > 0) {
    if (k % 2 == 1) {
      ret *= now;
      ret %= md;
    }
    now *= now;
    now %= md;
    k /= 2;
  }
  return ret;
}
long long gyaku(long long n, long long md) { return beki(n, md - 2, md); }
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  long long n;
  cin >> n;
  long long aa;
  cin >> aa;
  vector<long long> v;
  v.push_back(aa);
  for (long long i = 0; i < n - 1; i++) {
    char c;
    cin >> c;
    long long a;
    cin >> a;
    if (c == '+')
      v.push_back(a);
    else
      v.push_back(-a);
  }
  long long ans = 0;
  long long c = 0;
  for (long long i = 0; i < v.size(); i++) {
    if (v[i] < 0) {
      if (c == 0) {
        c = 1;
      } else
        c = 2;
    }
    if (c == 1)
      ans += -abs(v[i]);
    else
      ans += abs(v[i]);
  }
  cout << ans << endl;
}
