#include <bits/stdc++.h>
using namespace std;
#define mp make_pair
#define pb push_back
int main()
{
	int n;
	cin>>n;
	vector<pair<int,int> > v;
	for (int i=0; i<n; i++)
	{
		int x,y;
		cin>>x>>y;
		v.pb(mp(x,y));
	}
	int count=0;
	for (int i=0; i<v.size(); i++)
	{
		for (int j=i+1; j<v.size(); j++)
		{
			for (int k=j+1; k<v.size(); k++)
			{
				int area=v[i].first*(v[j].second-v[k].second)+v[j].first*(v[k].second-v[i].second)+v[k].first*(v[i].second-v[j].second);
				if (area!=0)
					++count;
			}
		}
	}
	cout<<count<<endl;
	return 0;
}

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NAowIDAKMSAwCjAgMQoxIDE=

4
0 0
1 0
0 1
1 1