#include <bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define R cin>>
#define Z class
#define ll long long
#define ln cout<<'\n'
#define in(a) insert(a)
#define pb(a) push_back(a)
#define pd(a) printf("%.10f\n",a)
#define mem(a) memset(a,0,sizeof(a))
#define all(c) (c).begin(),(c).end()
#define iter(c) __typeof((c).begin())
#define rrep(i,n) for(ll i=(ll)(n)-1;i>=0;i--)
#define REP(i,m,n) for(ll i=(ll)(m);i<(ll)(n);i++)
#define rep(i,n) REP(i,0,n)
#define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++)
template<Z A>void pr(A a){cout<<a;ln;}
template<Z A,Z B>void pr(A a,B b){cout<<a<<' ';pr(b);}
template<Z A,Z B,Z C>void pr(A a,B b,C c){cout<<a<<' ';pr(b,c);}
template<Z A,Z B,Z C,Z D>void pr(A a,B b,C c,D d){cout<<a<<' ';pr(b,c,d);}
template<Z A>void PR(A a,ll n){rep(i,n){if(i)cout<<' ';cout<<a[i];}ln;}
ll check(ll n,ll m,ll x,ll y){return x>=0&&x<n&&y>=0&&y<m;}
const ll MAX=1e9+7,MAXL=1LL<<61,dx[4]={-1,0,1,0},dy[4]={0,1,0,-1};
#define double long double
const double EPS=1e-10,pi=M_PI;
typedef complex<double> P;
double cross(const P& a, const P& b) {return imag(conj(a)*b);}
double dot(const P& a, const P& b) {return real(conj(a)*b);}
bool cmp(P a, P b) {
  double at=atan2(a.imag(),a.real()),at2=atan2(b.imag(),b.real());
  return at!=at2?at<at2:max(abs(a.real()),abs(a.imag()))<max(abs(b.real()),abs(b.imag()));
}
int ccw(P a, P b, P c) {
  b-=a;c-=a;
  if(cross(b,c)>EPS)return +1;
  if(cross(b,c)<-EPS)return -1;
  if(dot(b,c)<-EPS)return +2;
  if(norm(b)<norm(c))return -2;
  return 0;
}

void Main() {
  int n;
  cin >> n;
  vector<P> v(n);
  for(ll i=0; i<n; i++) {
    double x,y;
    cin >> x >> y;
    v[i]=P(x,y);
  }
  sort(v.begin(),v.end(),cmp);
  double d[n];
  rep(i,n) d[i]=atan2(v[i].imag(),v[i].real());
  ll ans=0;
  rep(i,n) {
    REP(j,i+1,n) {
      if(ccw(P(0,0),v[i],v[j])!=1) continue;
      ll k=lower_bound(d,d+n,d[j]+pi-EPS)-d-1;
      ll k2=upper_bound(d,d+n,d[i]+pi+EPS)-d;
      ans+=max(0LL,k-k2+1);
    }
  }
  pr(ans);
}

int main(){ios::sync_with_stdio(0);cin.tie(0);Main();return 0;}