#include<fstream>
using namespace std;
int trapez(long x1,long y1,long x2,long y2,long x3,long y3,long x4,long y4)
{
 int rez=0;
 if((y2-y1)*(x4-x3)==(x2-x1)*(y4-y3)) rez++;
 if((y3-y2)*(x4-x1)==(x3-x2)*(y4-y1)) rez++;
 if((y4-y2)*(x3-x1)==(x4-x2)*(y3-y1)) rez++;
 return rez;
}
int main()
{
 int i,j,k,l,n,rez=0;
 long x[1000],y[1000];
 ifstream fin("trapez.in");
 fin>>n;
 for(i=1;i<=n;i++)
	fin>>x[i]>>y[i];
 fin.close();
 for(i=1;i<n-2;i++)
 	for(j=i+1;j<n-1;j++)
 	   for(k=j+1;k<n;k++)
 	   	  for(l=k+1;l<=n;l++)
 	    	 	   {
 	    	   	   	rez+=trapez(x[i],y[i],x[j],y[j],x[k],y[k],x[l],y[l]);
				   }
 ofstream fout("trapez.out");
 fout<<rez;
 fout.close();
 return 0;
}