#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <cmath>
#include <iomanip>
#include <stack>
#include <queue>
#include <numeric>
#include <map>
#include <unordered_map>
#include <set>
#include <fstream>
#include <chrono>
#include <random>
#include <bitset>
#include <atcoder/all>
#define rep(i,n) for(int i=0;i<(n);i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) ((int)(x).size())
#define pb push_back
using ll = long long;
using namespace std;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
ll gcd(ll a, ll b) {return b?gcd(b,a%b):a;}
ll lcm(ll a, ll b) {return a/gcd(a,b)*b;}


int main(){
  int N; cin >> N;
  vector<pair<ll,ll>> P(N);
  rep(i,N){
    ll x,y; cin >> x >> y; P[i] = {x,y};
  }
  int ans = 0;
  rep(i,N){
    vector<pair<ll,ll>> Q;
    rep(j,N){
      if(i==j) continue;
      ll dx = P[j].first-P[i].first;
      ll dy = P[j].second-P[i].second;
      ll g = gcd(abs(dx),abs(dy));
      dx /= g; dy /= g;
      Q.pb({dx,dy});
    }
    sort(all(Q));
    int flag = 0;
    rep(i,sz(Q)-1){
      if(Q[i]==Q[i+1]) flag = 1;
    }
    ans += flag;
  }
  cout << ans << endl;
  return 0;
};