#include <bits/stdc++.h>

 using namespace std;

 const int maxn=+;

 const double eps=1e-,INF=0x7fffffff;

 int n,cnt;

 double k[(maxn*maxn)>>];

 struct pt{

     double x,y;

     pt(double x=,double y=):x(x),y(y){}

 }p[maxn];

 int dcmp(double x){ if(fabs(x)<eps) return ; return x<?-:; }

 double getk(pt a,pt b){

     if(dcmp(a.x-b.x)==) return INF;

     return (a.y-b.y)/(a.x-b.x);

 }

 int main(){

     scanf("%d",&n);

     for(int i=;i<=n;i++) scanf("%lf%lf",&p[i].x,&p[i].y);

     for(int i=;i<=n;i++)

         for(int j=i+;j<=n;j++)

             k[++cnt]=getk(p[i],p[j]);

     sort(k+,k+cnt+);

     int ans=;

     for(int i=;i<=cnt;i++) if(k[i]!=k[i-]) ans++;

     printf("%d\n",ans);

     return ;

 }