#include <cstdio>
#include <math.h>
#include <functional>
#include <vector>
#define pdd pair<double,double>
#define M_PI  3.14159265358979323846
#define eps 1e-4
#define x first
#define y second
 
using namespace std;
 
const double s60 = sin(60 * M_PI / 180.0);   
const double c60 = cos(60 * M_PI / 180.0);
const double offset = 50000.0;
const int nmax = 1502;
const int mod = 666013;
int n;
pdd v[nmax];
 
inline pair<pdd,pdd> getPoints(pdd a,pdd b) {
    return make_pair(
        make_pair(c60 * (a.x - b.x) - s60 * (a.y - b.y) + b.x,
                  s60 * (a.x - b.x) + c60 * (a.y - b.y) + b.y),
        make_pair(c60 * (a.x - b.x) + s60 * (a.y - b.y) + b.x,
                  - s60 * (a.x - b.x) + c60 * (a.y - b.y) + b.y ));
}
 
inline double dist(pdd a,pdd b) {
    return sqrt((a.x - b.x)*(a.x - b.x) + (a.y - b.y)*(a.y - b.y));
}
 
 
vector< pdd > h[mod];//4 decimals precison
inline void insert(pdd p) {
    int num1 = static_cast<int>(p.x*10000);
    int num2 = static_cast<int>(p.y*10000);
    int hash = 1ll*num1*num2%mod;
    h[hash].push_back(p);
}
 
inline bool isEqual(const double &a,const double &b) {
    return fabs(b - a) < eps;
}
 
inline bool findPoint(pdd p) {
    int num1 = static_cast<int>(p.x*10000);
    int num2 = static_cast<int>(p.y*10000);
    int hash = 1ll*num1*num2%mod;
    for(const auto &val : h[hash]) {
        if(isEqual(val.x,p.x) && isEqual(val.y,p.y)) {
            return true;
        }
    }
    return false;
}
 
inline void readData() {
    scanf("%d",&n);
    for(int i = 0;i < n;i++) {
        scanf("%lf %lf",&v[i].x,&v[i].y);
    }
}
 
inline int solve() {
    int ret = 0;
    for(int i = 0;i < n;i++) {
        v[i].x += offset;
        v[i].y += offset;
        insert(v[i]);
    }
    for(int i = 0;i < n;i++) {
        for(int j = i + 1;j < n;j++) {
            pair< pdd ,pdd > points = getPoints(v[i],v[j]);
            ret += findPoint(points.x) + findPoint(points.y);
        }
    }
    return ret/3;
}
 
int main()
{
    freopen("triang.in","r",stdin);
    freopen("triang.out","w",stdout);
    readData();
    printf("%d\n",solve());
    return 0;
}