#include <iostream>
#include <fstream>
#include <algorithm>
#include <cmath>
#define EPS 1e-3
using namespace std;
ifstream si("triang.in");
ofstream so("triang.out");
struct pct
{
    long double x,y,lg,u;
} v[1505],c[1505];
inline long double dist2(pct a,pct b)
{
    return (a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y);
}
inline bool cmp(pct a,pct b)
{
    if(fabs(a.lg-b.lg)<EPS)
        return (a.u<b.u);
    return a.lg<b.lg;
}
int main()
{
    int n;
    si>>n;
    for(int i=1;i<=n;++i)
    {
        si>>v[i].x>>v[i].y;
    }
    int ans=0;
    for(int i=1;i<=n;++i)
    {
        int m=0;
        for(int j=1;j<i;++j)
        {
            c[++m]=v[ j ];
            c[m].lg=dist2(v[i],v[j]);
            c[m].u=atan2(v[j].y-v[i].y,v[j].x-v[i].x);
        }
        sort(c+1,c+m+1,cmp);
        int k=1;
        for(int j=1;j<=m;++j)
        {
            while(k<j&&c[j].lg-c[k].lg>EPS)
                ++k;
            while(k<j&&fabs(c[j].lg-c[k].lg)<EPS&&dist2(c[k],c[j])-c[j].lg>EPS)
                ++k;

            if(k<j&&fabs(c[j].lg-c[k].lg)<EPS&&fabs(dist2(c[k],c[j])-c[j].lg)<EPS)
            {
                ++ans;
            }
        }
    }
    so<<ans<<'\n';
    return 0;
}