#include <cstdio>
#include <cmath>
#include <vector>
#include <map>
using namespace std;

#define X first
#define Y second

int main() {
    freopen("1.txt", "r", stdin);
    int n,r=0;
    scanf("%d", &n);
    vector<pair<int,int> > a(n);
    for(int i=0; i<n; i++)
        scanf("%d%d", &a[i].X, &a[i].Y);

    double k;
    map<double, int>::iterator it;
    for(int i=0; i<n; i++) {
        map<double, int> m;
        for(int j=0; j<i; j++) {
            if(a[i].Y == a[j].Y) k = 0.; else
            if(a[i].X == a[j].X) k = ~(1<<31); else
            k = (double)(a[j].Y-a[i].Y)/(double)(a[j].X-a[i].X);
            m[k]++;
        }
        for(it = m.begin(); it!=m.end(); it++)
            r += (it->second+1)*max(it->second-1,0);
    }
    printf("%d\n", r);
    return 0;
}