#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
#include <fstream>
#include <utility>
#include <functional>
#include <time.h>
#include <stack>
#include <array>
#define popcount __builtin_popcount
using namespace std;
typedef long long int ll;
typedef pair<ll, ll> P;
bool myon(ll x1, ll y1, ll x2, ll y2){
    ll s=x1*y2-x2*y1;
    if(s>0) return true;
    if(s==0){
        if(x1*x2+y1*y2>0) return true;
        else return false;
    }
    return false;
}
int main()
{
    int n;
    cin>>n;
    ll x[4040], y[4040];
    for(int i=0; i<n; i++){
        cin>>x[i]>>y[i];
    }
    vector<int> ind, ind1, ind2;
    for(int i=0; i<n; i++){
        if(myon(1, 0, x[i], y[i])) ind1.push_back(i);
        else ind2.push_back(i);
    }
    auto comp=[](ll x1, ll y1, ll x2, ll y2){ return x1*y2-x2*y1>0;};
    sort(ind1.begin(), ind1.end(), [&](int i, int j){ return comp(x[i], y[i], x[j], y[j]);});
    sort(ind2.begin(), ind2.end(), [&](int i, int j){ return comp(x[i], y[i], x[j], y[j]);});
    ind=ind1;
    for(auto i:ind2) ind.push_back(i);
    for(auto i:ind1) ind.push_back(i);
    for(auto i:ind2) ind.push_back(i);
    int l[4040], r[4040];
    int t=0;
    for(int i=0; i<n; i++){
        while(t<i+n && x[ind[i]]*y[ind[t]]-y[ind[i]]*x[ind[t]]>=0){
            t++;
        }
        l[i]=t%n;
      //cout<<l[i]<<endl;
    }
    t=0;
    for(int i=0; i<n; i++){
        while(t<i+n && myon(x[ind[i]], y[ind[i]], x[ind[t]], y[ind[t]])){
            t++;
        }
        r[i]=t%n;
      //cout<<r[i]<<endl;
    }
    ll ans=0;
    for(int i=0; i<n; i++){
        for(int j=i+1; j<n; j++){
            if(x[ind[i]]*y[ind[j]]-x[ind[j]]*y[ind[i]]<=0) continue;
          //cout<<i<<" "<<j<<" "<<l[i]<<" "<<r[j]<<endl;
            int a=((r[j]-l[i])%n+n)%n;
            ans+=a;
        }
    }
    cout<<ans/2<<endl;
    return 0;
}