#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 5;
long long n, m, ans, a, b, temp;
int t;
long long num[maxn];
long long mark[maxn];
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> num[i];
    num[i] = abs(num[i]);
  }
  sort(num, num + n);
  int l = 0, r = 0;
  while (l < n) {
    while (r < n && 2 * num[l] >= num[r]) {
      r++;
    }
    ans += r - l - 1;
    l++;
  }
  cout << ans << endl;
}
