#include <bits/stdc++.h>
using namespace std;
const double EPS = 1e-9;
const double PI = 3.14159265359;
vector<long long> primes;
void GeneratingPrimes(int top) {
  vector<bool> p(top + 1, 1);
  p[0] = p[1] = 0;
  for (int i = 2; i <= sqrt(top); i++) {
    if (!p[i]) continue;
    if (p[i]) {
      for (int j = i * i; j <= top; j += i) {
        p[j] = 0;
      }
    }
  }
  for (int i = 0; i < top + 1; i++)
    if (p[i]) primes.push_back(i);
}
long long gcd(long long a, long long b) { return (b == 0) ? a : gcd(b, a % b); }
void EXTgcd(long long a, long long b, int& x0, int& y0) {
  if (b == 0) {
    x0 = 1, y0 = 0;
    return;
  }
  EXTgcd(b, a % b, x0, y0);
  long long x1 = y0;
  long long y1 = x0 - (a / b) * y0;
  x0 = x1;
  y0 = y1;
}
long long POW(long long x, long long p, long long mod) {
  if (!p) return 1;
  long long ret = 1;
  while (p > 1) {
    if (p & 1) ret *= (x);
    ret %= mod;
    x *= x;
    x %= mod;
    p /= 2;
  }
  ret *= (x % mod);
  return ret;
}
long long power(long long x, long long y, long long p) {
  long long res = 1;
  x = x % p;
  while (y > 0) {
    if (y & 1) res = (res * x) % p;
    y = y >> 1;
    x = (x * x) % p;
  }
  return res;
}
double dist(double a, double b, double x, double y) {
  return sqrt(pow(a - x, 2) + pow(b - y, 2));
}
double dist3(double a, double b, double c, double x, double y, double z) {
  return sqrt(pow(a - x, 2) + pow(b - y, 2) + pow(c - z, 2));
}
int xadd[9] = {1, -1, 0, 1, -1, 0, 1, -1, 0};
int yadd[9] = {1, -1, 0, -1, 0, 1, 0, 1, -1};
long long n, ans = 0;
int main() {
  cin >> n;
  vector<long long> v;
  int z = 0;
  for (int i = 0; i < n; i++) {
    long long a;
    cin >> a;
    v.push_back(abs(a));
  }
  sort(v.begin(), v.end());
  int l = 0;
  for (int i = 0; i < n; i++) {
    while (v[l] * 2 < v[i]) l++;
    ans += (i - l);
  }
  cout << ans;
}
