#include<stdio.h>
#include<math.h>
#include<algorithm>
#define eps 1.e-3
using namespace std;
struct point
{
    double x,y;
};
point a[1505];
class cmp_points
{
public: inline bool operator()(const point &a,const point &b)
    {
        if(fabs(a.x-b.x)<eps)
            return a.y-b.y<=-eps;
        return a.x-b.x<=-eps;
    }
};
pair<point,point> get(point p1,point p2)
{
    point P1,P2;
    P1.x=0.5*(p1.x + p2.x)-sqrt(3.0)*0.5*(p2.y-p1.y);
    P1.y=0.5*(p1.y + p2.y)+sqrt(3.0)*0.5*(p2.x-p1.x);
    P2.x=0.5*(p1.x + p2.x)+sqrt(3.0)*0.5*(p2.y-p1.y);
    P2.y=0.5*(p1.y + p2.y)-sqrt(3.0)*0.5*(p2.x-p1.x);
    return make_pair(P1,P2);
}
int main()
{
    freopen("triang.in","r",stdin);
    freopen("triang.out","w",stdout);
    int n,i,j,nr=0;
    scanf("%d",&n);
    for(i=1;i<=n;i++)
        scanf("%lf%lf",&a[i].x,&a[i].y);
    sort(a+1,a+n+1,cmp_points());
    for(i=1;i<=n;i++)
        for(j=i+1;j<=n;j++)
        {
            pair<point,point> p(get(a[i],a[j]));
            if(binary_search(a+1,a+n+1,p.first,cmp_points()))
                nr++;
            if(binary_search(a+1,a+n+1,p.second,cmp_points()))
                nr++;
        }
    printf("%d\n",nr/3);
    return 0;
}