#include <stdio.h>
#include <string>
#include <cstring>
#include <stdlib.h>
#include <math.h>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <list>
#include <iterator>
#include <assert.h>
#pragma warning(disable:4996) 
 
typedef long long ll;
#define MIN(a, b) ((a)>(b)? (b): (a))
#define MAX(a, b) ((a)<(b)? (b): (a))
#define LINF 9223300000000000000
#define INF 2140000000
const long long MOD = 1000000007;
//const long long MOD = 998244353;
using namespace std;


int main(int argc, char* argv[])
{
    int nn;
    scanf("%d", &nn);

    vector<pair<ll,ll> > z;
    int i;
    for(i=0; i<nn; i++) {
        int x,y;
        scanf("%d%d", &x, &y);
        if(x==0 && y==0) continue;
        z.push_back(make_pair(x,y));
    }
    int siz=(int)z.size();

    ll ans0=0;
    int j;
    for(i=0; i<siz; i++) {
        ll cnt0=0, cnt1=0;
        for(j=0; j<siz; j++) {
            if(i==j) continue;
            ll tmp=z[i].first*z[j].second-z[i].second*z[j].first;
            if(tmp>0) {
                cnt0++;
            }
            else if(tmp==0) {
                cnt1++;
            }
        }
        ans0+=cnt0*(cnt0-1)/2+cnt0*cnt1;
    }

    ll ans=(ll)siz*(siz-1)*(siz-2)/6-ans0;
    printf("%lld\n", ans);


    return 0;
}