#include <iostream>
#include<math.h>
#include<fstream>
 
using namespace std;
ifstream fin("triang.in");
ofstream fout("triang.out");
double dist(double x1,double y1,double x2,double y2)
{
    return sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));
}
struct Coordpuncte
{
  double x,y;
}cp[1501];
 
int verifechi( double x1,double y1,double x2,double y2,double x3,double y3)
{
    if(dist(x1,y1,x2,y2)==dist(x2,y2,x3,y3) && dist(x1,y1,x2,y2)==dist(x1,y1,x3,y3))return 1;
 
}

 
 
int N,i,j,k,matrdist[10000],nrechi;
int main()
{
    fin>>N;
    for(i=1;i<=N;i++)fin>>cp[i].x>>cp[i].y;
    for(i=1;i<=N-2;i++)
     for(j= i + 1;j<=N-1;j++)
      for(k= j + 1;k<=N;k++)
         if(verifechi(cp[i].x,cp[i].y,cp[j].x,cp[j].y,cp[k].x,cp[k].y))nrechi++;
    fout<<nrechi;
    return 0;
}