using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.IO;
using System.Reflection;
using static System.Math;
using System.Numerics;
static class Program{
	const int mod=(int)1e9+7;
	static void Main(){
		Sc sc=new Sc();
		var n=sc.I;
		var d=new double[n][];
		var g=new double[n];
		for(int i = 0;i<n;i++) {
			d[i]=sc.Da3(false,0,true,0);
			g[i]=Atan2(d[i][1],d[i][0])*180/PI;
			d[i][2]=g[i];
		}
		Array.Sort(g);
		long ans=0;
		for(int i = 0;i<n-1;i++) {
			for(int j = i+1;j<n;j++) {
				var c1=d[i][2];
				c1+=Sign(c1)==1?-180:180;
				var c2=d[j][2];
				c2+=Sign(c2)==1?-180:180;
				if(c1>c2){
					var e=c1;
					c1=c2;
					c2=e;
				}
				if(Abs(c1+180-c2)<1e-12||Abs(c1-c2)<1e-12){continue;}
				if(c2-c1>180){
					ans+=n-g.Bs(c2+1e-12,false)+g.Bs(c1-1e-12,true)+1;
				}
				else{
					ans+=g.Bs(c2-1e-12,true)-g.Bs(c1+1e-12,false)+1;
				}
			}
		}
		Console.WriteLine("{0}",ans/3);
	}
}
static class Ex1{
	public static int Bs(this double[] a,double x,bool b){return Bs2(a,x,b,a.Length);}
	public static int Bs(this double[] a,double x,bool b,int ub){return Bs2(a,x,b,ub+1);}
	private static int Bs2(double[] a,double x,bool b,int ub){
		int lb=-1,mid=0;
		while(ub-lb>1){
			mid=(ub+lb)/2;
			if(a[mid]>=x){ub=mid;}
			else{lb=mid;}
		}
		return b?lb:ub;
	}
}

public class Sc{
	public int I{get{return int.Parse(Console.ReadLine());}}
	public long L{get{return long.Parse(Console.ReadLine());}}
	public double D{get{return double.Parse(Console.ReadLine());}}
	public string S{get{return Console.ReadLine();}}
	public int[] Ia{get{return Array.ConvertAll(Console.ReadLine().Split(),int.Parse);}}
	public long[] La{get{return Array.ConvertAll(Console.ReadLine().Split(),long.Parse);}}
	public double[] Da{get{return Array.ConvertAll(Console.ReadLine().Split(),double.Parse);}}
	public string[] Sa{get{return Console.ReadLine().Split();}}
	public object[] Oa{get{return Console.ReadLine().Split();}}
	public int[] Ia2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),int.Parse);}}
	public int[] Ia3(int a){return Array.ConvertAll((a.ToString()+" "+Console.ReadLine()).Split(),int.Parse);}
	public int[] Ia3(bool a,int b,bool c,int d){return Array.ConvertAll(((a?b.ToString()+" ":"")+Console.ReadLine()+(c?" "+d.ToString():"")).Split(),int.Parse);}
	public long[] La2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),long.Parse);}}
	public long[] La3(int a){return Array.ConvertAll((a.ToString()+" "+Console.ReadLine()).Split(),long.Parse);}
	public long[] La3(bool a,int b,bool c,int d){return Array.ConvertAll(((a?b.ToString()+" ":"")+Console.ReadLine()+(c?" "+d.ToString():"")).Split(),long.Parse);}
	public double[] Da3(bool a,int b,bool c,int d){return Array.ConvertAll(((a?b.ToString()+" ":"")+Console.ReadLine()+(c?" "+d.ToString():"")).Split(),double.Parse);}
	public T[] Arr<T>(int n,Func<T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f();}return a;}
	public T[] Arr<T>(int n,Func<int,T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i);}return a;}
	public T[] Arr<T>(int n,Func<string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(Console.ReadLine().Split());}return a;}
	public T[] Arr<T>(int n,Func<int,string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i,Console.ReadLine().Split());}return a;}
}