// Problema trapez

#include <stdio.h>
#define MAX       1001

long X[MAX], Y[MAX];

int main()
{
    int i, n;
    freopen( "trapez.in" ,"rt", stdin );
             scanf( "%d", &n );
             for( i=1; i<=n; i++ )
                  scanf( "%ld %ld", &X[i], &Y[i] );
    fclose( stdin );
    
    long nr = 0;
    int j, k, l;
    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++ )
                        {
                         if( (Y[l] - Y[k])*(X[j]-X[i]) == (Y[j]-Y[i])*(X[l]-X[k]) ) nr++;
                         if( (Y[l] - Y[j])*(X[k]-X[i]) == (Y[k]-Y[i])*(X[l]-X[j]) ) nr++;
                         if( (Y[l] - Y[i])*(X[k]-X[j]) == (Y[k]-Y[j])*(X[l]-X[i]) ) nr++;
                        }
    
    freopen( "trapez.out", "wt", stdout );
             printf( "%ld\n", nr );
    fclose( stdout );
    return 0;
}