#include<fstream>
#include<cmath>
using namespace std;
int n,i,j,k,con;
struct punct
{
    float x,y;
}a[1501];
float dist1,dist2,dist3;
float distanta(float x1,float y1,float x2,float y2)
{
    float rez;
    rez=sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));
    if(rez<0)
    rez=-rez;
    return rez;
}
int main()
{
    ifstream f("triang .in");
    ofstream g("triang.out");
    f>>n;
    for(i=1;i<=n;i++)
    f>>a[i].x>>a[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(distanta(a[i].x,a[i].y,a[j].x,a[j].y)==distanta(a[i].x,a[i].y,a[k].x,a[k].y)==distanta(a[j].x,a[j].y,a[k].x,a[k].y))
            con++;
    g<<con;
    return 0;
}