import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

public class Main implements Runnable{

	public static void main(String[] args) {
		new Thread(null,new Main(), "" ,Runtime.getRuntime().maxMemory()).start();
	}
	
	public void run() {
		Scanner sc=new Scanner(System.in);
		int N=sc.nextInt();
		long[][] P=new long[N][2];
		for(int i=0;i<N;++i) {
			P[i][0]=sc.nextLong();
			P[i][1]=sc.nextLong();
		}
		Arrays.sort(P, new Comparator<long[]>() {
			@Override
			public int compare(long[] o1, long[] o2) {
				double ang1=Math.atan2(o1[1], o1[0]);
				double ang2=Math.atan2(o2[1], o2[0]);
				if(ang1<0)ang1+=Math.PI*2;
				if(ang2<0)ang2+=Math.PI*2;
				if(Math.abs(ang1-ang2)>Math.PI/4)return Double.compare(ang1, ang2);
				return Long.signum(-(o1[0]*o2[1]-o1[1]*o2[0]));
			}
		});
		long ans=0;
		for(int i=0;i+1<N;++i) {
			if(P[i][1]<0||(P[i][1]==0&&P[i][0]<0))break;
			int first=i+1;
			while(first<N&&P[i][0]*P[first][1]-P[i][1]*P[first][0]>=0)++first;
			int last=first;
			for(int j=i+1;j<first;++j) {
				if(P[i][0]*P[j][1]-P[i][1]*P[j][0]<=0)continue;
				while(last<N&&P[j][0]*P[last][1]-P[j][1]*P[last][0]>0)++last;
				ans+=last-first;
			}
		}
		System.out.println(ans);
	}
	
	void tr(Object...objects) {System.out.println(Arrays.deepToString(objects));}
}