#include <bits/stdc++.h>
using namespace std;
template <class T>
bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
bool chmin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &vec) {
  for (auto &v : vec) is >> v;
  return is;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &vec) {
  for (int i = 0; i < vec.size(); i++) {
    os << vec[i];
    if (i + 1 != vec.size()) os << " ";
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const set<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end()) os << " ";
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const unordered_set<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end()) os << " ";
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const multiset<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end()) os << " ";
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const unordered_multiset<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end()) os << " ";
  }
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  os << p.first << " " << p.second;
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const map<T1, T2> &mp) {
  for (auto itr = mp.begin(); itr != mp.end(); ++itr) {
    os << itr->first << ":" << itr->second;
    auto titr = itr;
    if (++titr != mp.end()) os << " ";
  }
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const unordered_map<T1, T2> &mp) {
  for (auto itr = mp.begin(); itr != mp.end(); ++itr) {
    os << itr->first << ":" << itr->second;
    auto titr = itr;
    if (++titr != mp.end()) os << " ";
  }
  return os;
}
using ll = long long int;
using P = pair<int, int>;
const int inf = 1e9;
const ll linf = 1LL << 50;
const double EPS = 1e-10;
const int mod = 1000000007;
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};
struct fast_io {
  fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(20);
  }
} fast_io_;
ll dp[100010][2][2];
int main(int argc, char const *argv[]) {
  int n;
  cin >> n;
  vector<ll> a(n);
  vector<string> op(n - 1);
  cin >> a[0];
  for (int i = (0); i < (n - 1); ++i) cin >> op[i] >> a[i + 1];
  for (int i = (0); i < (n); ++i)
    for (int j = (0); j < (2); ++j)
      for (int k = (0); k < (2); ++k) dp[i][j][k] = -linf;
  dp[0][0][0] = a[0];
  for (int i = (0); i < (n - 1); ++i) {
    if (op[i] == "+") {
      chmax(dp[i + 1][0][0], dp[i][0][0] + a[i + 1]);
      chmax(dp[i + 1][0][1], dp[i][0][1] + a[i + 1]);
      chmax(dp[i + 1][1][1], dp[i][0][1] + a[i + 1]);
      chmax(dp[i + 1][1][1], dp[i][1][1] - a[i + 1]);
      chmax(dp[i + 1][0][1], dp[i][1][1] - a[i + 1]);
      chmax(dp[i + 1][0][1], dp[i][1][1] - a[i + 1]);
    } else {
      chmax(dp[i + 1][0][0], dp[i][0][0] - a[i + 1]);
      chmax(dp[i + 1][0][1], dp[i][0][1] - a[i + 1]);
      chmax(dp[i + 1][1][1], dp[i][0][1] - a[i + 1]);
      chmax(dp[i + 1][0][1], dp[i][1][1] + a[i + 1]);
      chmax(dp[i + 1][1][1], dp[i][1][1] + a[i + 1]);
      chmax(dp[i + 1][0][1], dp[i][1][1] + a[i + 1]);
      chmax(dp[i + 1][1][1], dp[i][0][0] - a[i + 1]);
      chmax(dp[i + 1][1][1], dp[i][0][1] - a[i + 1]);
      chmax(dp[i + 1][0][1], dp[i][1][1] + a[i + 1]);
    }
  }
  cout << max(dp[n - 1][0][0], dp[n - 1][0][1]) << endl;
  return 0;
}
