#include<stdio.h>
#include<math.h>
FILE*f=fopen("triang.in","r");
FILE*g=fopen("triang.out","w");
float x[1501],y[1501];
int n;
void read()
	{
	int i;
	fscanf(f,"%d",&n);
	for(i=1;i<=n;++i) fscanf(f,"%f %f",&x[i],&y[i]);
	}
int dist(float x1,float y1,float x2,float y2)
	{
	float d;
	d=sqrt((x1-x2)*(x1-x2)-(y1-y2)*(y1-y2));
	return d;
	}
void calcul()
	{
	long i,sol=0;
	long j;
	float a,b,c;
	for(i=1;i<n-1;++i)
		for(j=i+1;j<n;++j)
			{
			a=dist(x[i],y[i],x[j],y[j]);
			for(int p=j+1;p<=n;++p)
			   {
				b=dist(x[i],y[i],x[p],y[p]);
				c=dist(x[j],y[j],x[p],y[p]);
				if(a==b&&b==c) sol++;
			   }
			}
	fprintf(g,"%ld",sol);
	}
int main()
	{
	read();
	calcul();
	return 0;
        }