#include <bits/stdc++.h>
using namespace std;
#define int              long long int
#define double           long double
#define print(a)         for(auto x : a) cout << x << " "; cout << endl
inline int power(int a, int b) {
    int x = 1;
    while (b) {
        if (b & 1) x *= a;
        a *= a;
        b >>= 1;
    }
    return x;
}


const int M = 1000000007;
const int N = 3e5+9;
const int INF = 2e9+1;
const int LINF = 2000000000000000001;

//_ ***************************** START Below *******************************

vector<int> a;

int consistency(int n){
	
	vector<int> b;
	unordered_set<int> st;
	for(int i=0; i<n; i++){
	    if(!st.count(a[i])){
		    b.push_back(abs(a[i]));
	    }
	    st.insert(a[i]);
	}
	sort(begin(b), end(b));
	
	int m = b.size();
	
	int ans = 0;
	for(int i=0; i<m-1; i++){
		int j = upper_bound(begin(b)+i+1, end(b), 2*b[i] ) - begin(b);
	
		ans += (j-1)-i;
	}
	
	return ans;
}










void solve() {
    
    int n;
    cin>>n;
    a.resize(n);
    
    for(int i=0; i<n; i++) cin >> a[i];
    cout << consistency(n) << endl;


}






int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }

    return 0;
}