#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001

void go(long long &x,long long &y){
	long long g = gcd(abs(x),abs(y));
	x /= g;
	y /= g;
	if(x==0){
		if(y<0)y *= -1;
	}
	else if(x<0){
		x *= -1;
		y *= -1;
	}
}

int main(){
	
	int N;
	cin>>N;
	
	vector<long long> x(N),y(N);
	rep(i,N)cin>>x[i]>>y[i];
	
	vector<bool> f(N,false);
	rep(i,N){
		map<pair<long long,long long>,vector<pair<pair<long long,long long>,int>>> mp;
		rep(j,N){
			if(i==j)continue;
			long long dx = x[j] - x[i],dy = y[j] - y[i];
			go(dx,dy);
			mp[make_pair(dx,dy)].emplace_back(make_pair(x[j],y[j]),j);
		}
		for(auto a:mp){
			auto t = a.second;
			t.emplace_back(make_pair(x[i],y[i]),i);
			sort(t.begin(),t.end());
			if(t.size()>=3){
				rep(j,t.size()){
					if(t.size()==3&&j==1)continue;
					f[t[j].second] = true;
				}
			}
		}
	}
	int ans = 0;
	rep(i,N){
		if(f[i])ans++;
	}
	
	cout<<ans<<endl;
	
	return 0;
}