#include<bits/stdc++.h>
//ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<pii,int> ppii;
typedef pair<int,pii> pipi;
typedef pair<ll,ll> pll;
typedef pair<pll,ll> ppll;
typedef pair<ll,pll> plpl;
typedef tuple<ll,ll,ll> tl;
ll mod=1000000007;
ll mod2=998244353;
ll mod3=1000003;
ll mod4=998244853;
ll inf=1000000000;
double pi=2*acos(0);
#define rep(i,m,n) for(ll i=m;i<n;i++)
#define rrep(i,n,m) for(ll i=n;i>=m;i--)
int dh[4]={1,-1,0,0};
int dw[4]={0,0,1,-1};
int ddh[8]={-1,-1,-1,0,0,1,1,1};
int ddw[8]={-1,0,1,-1,1,-1,0,1};
ll lmax(ll a,ll b){
    if(a<b)return b;
    else return a;
}
ll lmin(ll a,ll b){
    if(a<b)return a;
    else return b;
}
ll gcd(ll a,ll b){
    if(a<b)swap(a,b);
    if(b==0)return a;
    if(a%b==0)return b;
    return gcd(b,a%b);
}
ll Pow(ll n,ll k){
    ll ret=1;
    ll now=n;
    while(k>0){
        if(k&1)ret*=now;
        now*=now;
        k/=2;
    }
    return ret;
}
ll beki(ll n,ll k,ll md){
  ll ret=1;
  ll now=n;
  while(k>0){
    if(k%2==1){
      ret*=now;
      ret%=md;
    }
    now*=now;
    now%=md;
    k/=2;
  }
  return ret;
}
ll gyaku(ll n,ll md){
  return beki(n,md-2,md);
}
int main(){
    ios::sync_with_stdio(false);cin.tie(0);
    int n;cin>>n;
    //cout<<acos(0.5)*180/pi;return 0;
    vector<double> v;
    rep(i,0,n){
        ll a,b;cin>>a>>b;
        if(a==0&&b==0)continue;
        double r=pow(a*a+b*b,0.5);
       // cout<<r<<endl;
        if(b>=0){
            v.push_back(180*acos(a/r)/pi);
        }
        else{
            v.push_back(360-acos(a/r)*180/pi);
        }
    }//return 0;
    sort(v.begin(),v.end());
    //rep(i,0,v.size())cout<<v[i]<<" ";
    ll ans=0;
    rep(i,0,v.size()){
        ll dp[v.size()][3];
        memset(dp,0,sizeof dp);
        dp[i][0]=1;
        rep(j,i,v.size()){
            int y=lower_bound(v.begin(),v.end(),v[j]+180)-v.begin();
            y--;
            if(y==j)continue;
            rep(l,0,2){
                rep(k,j+1,y+1)dp[k][l+1]+=dp[j][l];
            }
        }
        rep(j,i+1,v.size()){
            if(v[i]+360-v[j]<180)ans+=dp[j][2];
        }
        
    }
    cout<<ans<<endl;
}