#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using ld=long double;
ld pie=3.141592653589793;
ll inf=200000000000000;
ll mod=998244353;
ll gcd(ll a, ll b) {
	a = abs(a); b = abs(b);
	if (a < b)swap(a, b);
	while (b) {
	    ll r=a%b;
        a=b;
	    b=r;
	}
	return a;
}
int main(){
    ll n;
    cin >> n;
    vector<ll>x(n),y(n);
    for (ll i = 0; i < n; i++)
    {
        cin >> x[i] >> y[i];
    }
    ll ans=0;
    for (ll i = 0; i < n; i++)
    {
        map<pair<ll,ll>,ll>memo;
        for (ll j = 0; j < n; j++)
        {
            if (i==j)
            {
                continue;
            }
            ll xx=(x[i]-x[j]),yy=y[i]-y[j];
            ll z=gcd(abs(xx),abs(yy));
            xx/=z;
            yy/=z;
            memo[{xx,yy}]+=1;
            if (memo[{xx,yy}]>=2)
            {
                ans++;
                break;
            }
        }
    }
    cout << ans << endl;
}