#include <iostream>
#include <stdio.h>
#include <cmath>

using namespace std;

FILE *f=fopen("triang.in","r");
FILE *g=fopen("triang.out","w");




int n,nr,i,j,k;
double d1,d2,d3;
struct pct
{
    double x,y;
}v[2000],x,y,z;




double dist(pct x,pct y)
{
    double x1,y1,fin;
    x1=fabs(x.x-y.x);
    y1=fabs(x.y-y.y);
    fin=x1*x1+y1*y1;
    fin=sqrt(fin);
    return fin;
}


int main()
{
    fscanf(f,"%d",&n);
    nr=0;
    for(i=1;i<=n;i++)
    fscanf(f,"%lf%lf",&v[i].x,&v[i].y);
    for(i=1;i<=n;i++)
    for(j=i+1;j<=n;j++)
    for(k=j+1;k<=n;k++)
    {
        x=v[i];
        y=v[j];
        z=v[k];
        d1=dist(x,y);
        d2=dist(x,z);
        d3=dist(y,z);
       if(fabs(d1-d2)<0.001 && fabs(d1-d3)<0.001)nr++;
    }
    fprintf(g,"%d",nr);
    fclose(g);
    return 0;
}