#include<stdio.h>
#include<math.h>
FILE*f=fopen("triang.in","r");
FILE*g=fopen("triang.out","w");
int x[1501],y[1501];
int n;
void read()
	{
	int i;
	fscanf(f,"%d",&n);
	for(i=1;i<=n;++i) fscanf(f,"%d %d",&x[i],&y[i]);
	}
int dist(int x1,int y1,int x2,int y2)
	{
	int d;
	d=(int)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;
        }