#include <stdio.h>
#include <stdlib.h>
int v[1000][2];

int test(int a,int b, int c, int d)
{
    int n=0;

    if((v[a][0]-v[b][0])*(v[c][1]-v[d][1])==((v[c][0]-v[d][0])*(v[a][1]-v[b][1]))) n++;
    if((v[a][0]-v[c][0])*(v[b][1]-v[d][1])==((v[b][0]-v[d][0])*(v[a][1]-v[c][1]))) n++;
    if((v[a][0]-v[d][0])*(v[c][1]-v[b][1])==((v[c][0]-v[b][0])*(v[a][1]-v[d][1]))) n++;
    return n;
}

int main()
{
    FILE * fp=fopen("trapez.in","r");
    FILE * f=fopen("trapez.out","w");
    int n,N=0,a,b,c,d;

    fscanf(fp,"%d\n",&n);

    for(a=0;a<n;a++)
    {
        fscanf(fp,"%d %d",&v[a][0],&v[a][1]);
    }

    for(a=0;a<n;a++)
    {
        for(b=a+1;b<n;b++)
        {
            for(c=b+1;c<n;c++)
            {
                for(d=c+1;d<n;d++)
                {
                    N+=test(a,b,c,d);
                }
            }
        }
    }

    fprintf(f,"%d",N);

    return 0;
}