#include <bits/stdc++.h>
using namespace std;
using ii = pair<int, int>;
using ll = long long;
using vi = vector<int>;
template <typename T>
using minheap = priority_queue<T, vector<T>, greater<T>>;
template <typename T>
using maxheap = priority_queue<T>;
template <typename T>
ostream& operator<<(ostream& os, vector<T> v) {
  os << "[ ";
  for (auto e : v) os << e << " ";
  return os << "]";
}
template <typename T, typename V>
ostream& operator<<(ostream& os, set<T, V> v) {
  os << "{ ";
  for (auto e : v) os << e << " ";
  return os << "}";
}
template <typename T, typename V, typename S>
ostream& operator<<(ostream& os, map<T, V, S> v) {
  os << "{ ";
  for (auto e : v) os << e << " ";
  return os << "}";
}
template <typename T, typename V>
ostream& operator<<(ostream& os, pair<T, V> x) {
  return os << "( " << x.first << ", " << x.second << " )";
}
template <typename T>
istream& operator>>(istream& is, vector<T>& v) {
  for (auto& e : v) is >> e;
  return is;
}
template <typename T, typename V>
istream& operator>>(istream& is, pair<T, V>& x) {
  return is >> x.first >> x.second;
}
void solve();
int main() { solve(); }
int n, m = 0;
ll press[200005];
int freq[200005];
map<int, int> occ;
void solve() {
  scanf("%d", &n);
  for (int i = 0; i < n; ++i) {
    int a;
    scanf("%d", &a);
    if (a < 0) a = -a;
    ++occ[a];
    press[m++] = a;
  }
  sort(press, press + m);
  m = unique(press, press + m) - press;
  if (0) cout << vector<int>(press, press + m) << "\n";
  for (int i = 0; i < m; ++i) {
    int cnt = occ[press[i]];
    freq[i] = cnt;
  }
  ll ans = 0;
  int r = -1;
  ll sum = 0;
  for (int i = 0; i < m; ++i) {
    while (r + 1 < m && press[r + 1] <= 2LL * press[i]) {
      ++r;
      sum += freq[r];
    }
    if (0)
      cout << "i"
              " = "
           << (i)
           << " "
              "sum"
              " = "
           << (sum)
           << " "
              "r"
              " = "
           << (r) << "\n";
    ;
    ans += 1LL * freq[i] * (sum - freq[i]);
    ans += 1LL * freq[i] * (freq[i] - 1) / 2;
    sum -= freq[i];
  }
  cout << ans << "\n";
}
