#include<stdio.h>
#include<stdlib.h>
#include<algorithm>
#define NMAX 1502
#define x first
#define y second
#define EPS 0.0001
#define MEPS -0.0001
#define FIN "triang.in"
#define FOUT "triang.ok"
#include<math.h>
#include<vector>
using namespace std;


double abs(double a)
{
    if(a < EPS) return (-a);
    return a;
    }
const double  PI = 3.14159265;
int N,REZ;
double d[NMAX][NMAX];
pair<double,double> P[NMAX];
//vector<int,int,int> test;
int comp(pair<double,double> a,pair<double,double> b)
{
    if( abs(a.x - b.x) < EPS ) return (a.y - b.y) < EPS;
    return (a.x - b.x) < EPS;
    }

int main()
{
    freopen(FIN,"r",stdin);
    freopen(FOUT,"w",stdout);
    scanf("%d",&N);
     for(int i = 1 ; i <= N ;i++ )
       scanf("%lf %lf",&P[i].x,&P[i].y);
     for(int i =1 ;i<= N;i++)
      for(int j =i+1 ;j<=N;j++)
       for(int k =j+1 ;k<=N;k++)
        {
            double d1,d2,d3;
            d1 = (P[i].x -P[j].x) *(P[i].x -P[j].x)+(P[i].y -P[j].y) *(P[i].y -P[j].y);
            d2 = (P[k].x -P[j].x) *(P[k].x -P[j].x)+(P[k].y -P[j].y) *(P[k].y -P[j].y);
            d3 = (P[i].x -P[k].x) *(P[i].x -P[k].x)+(P[i].y -P[k].y) *(P[i].y -P[k].y);
            printf("%lf %lf %lf\n",d1,d2,d3);
            if(MEPS<(d1-d2) && (d1-d2)<EPS && MEPS<(d3-d2) && (d3-d2)<EPS) REZ++;
            }   
       printf("%d",REZ);
    return 0;
}