#include<bits/stdc++.h>
using namespace std;
#define INIT  ios_base :: sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define mp make_pair
#define pb push_back
#define ft first
#define sc second
#define ll long long
#define pii pair<int, int>
#define count_bits __builtin_popcount
#define int ll


ifstream f1("trapez.in"); ofstream f2("trapez.out");
#define cin f1
#define cout f2


int t, n, x[1010], y[1010];
map<pii, bool> v[1010];
map<pii, int> h[1010];
set<pair<pii, int>> ss;
map<pii, int> sum;
set<pii> s[1010];


int32_t main(){
INIT
cin>>n;
for(int i=1; i<=n; i++){
    cin>>y[i]>>x[i];
}



for(int i=1; i<=n; i++){
    for(int j=i+1; j<=n; j++){
        int dx=x[j]-x[i], dy=y[j]-y[i]; int gcd=__gcd(dx, dy); dx/=gcd; dy/=gcd;
        if(dx<0){dx=-dx; dy=-dy;}
        if(v[i][mp(dx, dy) ]==true){continue;}
        v[i][mp(dx, dy) ]=true;v[j][ mp(dx, dy)]=true;
        h[i][mp(dx, dy) ]++;
        s[i].insert(mp(dx, dy));
    }

    while(!s[i].empty()){
        pii f=(*s[i].begin()); s[i].erase(s[i].begin());
        int pt=h[i][f]+1; int ln=(pt*(pt-1))/2;
        ss.insert(mp(f, ln) );
        sum[f]+=ln; sum[(mp(-f.ft, -f.sc)) ]+=ln;
    }
}

int cnt=0;
while(!ss.empty()){
    pair<pii, int> f=(*ss.begin()); ss.erase(ss.begin());
    sum[f.ft]-=f.sc;
    cnt+=sum[f.ft]*(f.sc);
}
cout<<cnt;





return 0;
}