#include<bits/stdc++.h>
using namespace std;
long long n,ans;
struct zbz{
	long long x,y;
}zb[2005];
double jlgs(long long zb1,long long zb2){
    return double(sqrt((zb[zb1].x-zb[zb2].x)*(zb[zb1].x-zb[zb2].x)
	+(zb[zb1].y-zb[zb2].y)*(zb[zb1].y-zb[zb2].y)));
}
bool sjx(long long zb1,long long zb2,long long zb3){
	if(jlgs(zb1,zb2)+jlgs(zb1,zb3)>jlgs(zb2,zb3)
		and jlgs(zb1,zb3)+jlgs(zb2,zb3)>jlgs(zb1,zb2)
		and jlgs(zb1,zb2)+jlgs(zb2,zb3)>jlgs(zb1,zb3))
	return true;
	return false;
}
bool dy(long long zb1,long long zb2,long long zb3){
	if(jlgs(zb1,zb2)==jlgs(zb1,zb3)
		or jlgs(zb1,zb2)==jlgs(zb2,zb3)
		or jlgs(zb1,zb3)==jlgs(zb2,zb3))
	return true;
	return false;
}
int main(){
	cin>>n;
	for(long long i=0;i<n;i++)cin>>zb[i].x>>zb[i].y;
	for(long long i=0;i<n;i++)
		for(long long j=i;j<n;j++)
			for(long long k=j;k<n;k++)
				if(sjx(i,j,k) and dy(i,j,k))ans++;
	cout<<ans;
	return 0;
}