#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

typedef __int128_t T;
bool F(T d,T e,T f,T g,T h,T i,T m,T n){
	return (f-d)*(n-e)*(f=(h-f)*(n-g)-(m-f)*(i-g))>f*(m-d)*(g-e)&f*(d-h)*(n-i)>f*(m-h)*(e-i);
}
int X[4000],Y[4000];
typedef struct{
	int i;
	long long R;
}tR;
tR* process(tR* R){
	//R->R=0;
	int i=R->i;
	long long r=0;
	for(int j=0;j<i;j++)for(int k=0;k<j;k++){
		if(F(X[i],Y[i],X[j],Y[j],X[k],Y[k],0,0))r++;
	}
	R->R=r;
	return R;
}

int main(){
	long long r=0;
	int n=0;
	scanf("%d",&n);
	for(int i=0;i<n;i++)scanf("%d%d",X+i,Y+i);

	int nthreads=1;
	//pthread_t *threads=(pthread_t*)alloca(sizeof(pthread_t)*nthreads);
	for(int i=0;i<n;i+=nthreads){
		tR *Rmain;
		int i0=0;
		for(;i0<nthreads;i0++){
			if(i+i0>=n)break;
			tR *R=malloc(sizeof(tR));
			R->i=i+i0;
			if(i0<nthreads-1){
				//pthread_create(&threads[i0],NULL,(void*(*)(void*))process,R);
			}else{
				Rmain=R;
				process(R);
			}
		}
		for(int i1=0;i1<i0;i1++){
			tR *R;
			if(i1<nthreads-1){
				//pthread_join(threads[i1],(void**)&R);
			}else{
				R=Rmain;
			}
			r+=R->R;
			free(R);
		}
	}
	printf("%lld\n",r);
}