#include <bits/stdc++.h>

using namespace std;

#define int long long
#define ll long long
#define forn(i, n) for (ll i = 0; i < n; ++i)
#define forr(i, s, n) for (ll i = s; i < n; ++i)
#define fori(i, s, n) for (ll i = s; i > n; --i)
#define fora(i, n) for (auto i: n)
#define vi vector<int>
#define vll vector<ll>
#define prints(n) cout << (n) << " "
#define println(n) cout << (n) << "\n"

const int MOD = 998244353;
// const int MOD = 1e9 + 7;



 template <class T> int sgn(T x){return (x>0)-(x<0);}
 template<class T>
 struct Point{
 typedef Point P;
 T x,y;
 explicit Point(T x=0,T y=0):x(x),y(y){}
 bool operator<(P p) const{return tie(x,y)<tie(p.x,p.y);}
 bool operator==(P p)const{return tie(x,y)==tie(p.x,p.y);}
 P operator+(P p) const{return P(x+p.x,y+p.y);}
 P operator-(P p) const{return P(x-p.x,y-p.y);}
 P operator*(T d) const{return P(x*d,y*d);}
 P operator/(T d) const{return P(x/d,y/d);}
 T dot(P p) const{return x*p.x+y*p.y;}
 T cross(P p) const{return x*p.y-y*p.x;}
 T cross(P a,P b) const{return (a-*this).cross(b-*this);}
 T dist2() const{return x*x+y*y;}
 double dist() const{return sqrt((double)dist2());}
 // angle to x axis in interval [ pi, pi]
 double angle() const{return atan2(y,x);}
 P unit() const{return *this/dist();}//makes dist()=1
 P perp() const{return P(-y,x);}// rotates+90degrees
 P normal() const{return perp().unit();}
 // returns point rotated a radians ccwaround the origin
 P rotate(double a) const{
 return P(x*cos(a)-y*sin(a),x*sin(a)+y*cos(a));}
 friend ostream& operator<<(ostream&os,P p){
 return os<<"("<<p.x<<","<<p.y<<")";}
 };

typedef Point<long long> P;
vector<P> point;


class Compare
{
public:
    bool operator() (const P& a, const P& b)
    {
        return true;
    }
};

void solve() {

    int n;
    cin >> n;
    point.resize(n);
    for (auto& i : point) cin >> i.x >> i.y;


    int nonConvex = 0, convex = 0;
    for (int i = 0;i < point.size();i++){
        for (int j = i+1;j < point.size();j++){
            vector<P> lP;
            vector<P> rP;
            for (int k = 0;k < point.size();k++){
                if (k == i || k == j) continue;
                if (point[i].cross(point[j],point[k]) > 0) lP.push_back(point[k]);
                else rP.push_back(point[k]);
            }
            // cout << "i " << i << " " << j << endl;

            auto smallerAngleA = [&] (const P& a, const P& b){
                return point[i].cross(a,b) >= 0;
            };

            auto smallerAngleB = [&] (const P& a, const P& b){
                return point[j].cross(a,b) <= 0;
            };

            auto smallerAngleAInv = [&] (const P& a, const P& b){
                return point[i].cross(a,b) <= 0;
            };

            auto smallerAngleBInv = [&] (const P& a, const P& b){
                return point[j].cross(a,b) >= 0;
            };


            vector<P> valLP;
            vector<P> valRP;

            sort(lP.begin(), lP.end(), smallerAngleA);

            priority_queue<P, vector<P>, decltype(smallerAngleBInv)> pq(smallerAngleBInv);
            for (int k = 0;k < lP.size();k++){
                pq.push(lP[k]);
                // cout << "top: "<< pq.top() << endl;
                if (lP[k] == pq.top()){
                    valLP.push_back(lP[k]);

                }
            }

            sort(rP.begin(), rP.end(), smallerAngleBInv);

            // cout << "rp sorted:\n";
            // for (auto i : rP){
            //     cout << i << endl;
            // }
            // cout << "-----\n";      

            priority_queue<P, vector<P>, decltype(smallerAngleA)> pq2(smallerAngleA);
            for (int k = 0;k < rP.size();k++){
                pq2.push(rP[k]);
                if (rP[k] == pq2.top()){
                    valRP.push_back(rP[k]);
                }
            }

            // cout << "lp:\n";
            // for (auto i : valLP){
            //     cout << i << endl;
            // }
            // cout << "-----\n";
            // cout << "rp:\n";
            // for (auto i : valRP){
            //     cout << i << endl;
            // }
            // cout << "-----\n";

            for (int k = 0;k < valLP.size();k++){
                // cout << "masukk\n";
                int idkiri = upper_bound(valRP.begin(),valRP.end(),true, [&] (bool val, const P& a){
                    return !(valLP[k].cross(point[i],a) < 0);
                }) - valRP.begin() - 1 ;
                int idkanan = upper_bound(valRP.begin(),valRP.end(),true, [&] (bool val, const P& a){
                    return !(valLP[k].cross(point[j],a) < 0);
                }) - valRP.begin() - 1;
                // cout << idkiri << " " << idkanan << endl;
                int addconvex = idkanan-idkiri;
                int addnon = valRP.size()-addconvex;
                convex += addconvex;
                nonConvex += addnon;

                // cout << "hasil nonconvex :" << nonConvex << endl;
                // cout << "hasil convex :" << convex << endl;
            }


        }
    }
    // cout << nonConvex << " " << convex <<
    cout << nonConvex + convex/2 << endl;
}

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);

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

    return 0;
}