#include<stdio.h>

#define nmax 1001

int x[nmax],y[nmax];

int main()
{
    int n,cont=0;
    freopen("trapez.in","r",stdin);
    freopen("trapez.out","w",stdout);
    scanf("%d",&n);
    for(int i=1;i<=n;++i)
        {
            scanf("%d%d",&x[i],&y[i]);
            for(int j=i-1;j;j--)
                for(int k=j-1;k;k--)
                    for(int l=k-1;l;l--)
                        if (  (x[k]-x[l])*(y[j]-y[i])==(y[k]-y[l])*(x[j]-x[i]) || (x[i]-x[k])*(y[j]-y[l])==(y[i]-y[k])*(x[j]-x[l]) ||  (x[i]-x[l])*(y[j]-y[k])==(y[i]-y[l])*(x[j]-x[k])  )
                            ++cont;
        }
    printf("%d\n",cont);
    return 0;
}