1464.cpp

#include <bits/stdc++.h>
#define _ ios_base::sync_with_stdio(0);cin.tie(0);
using namespace std;

#define INF 1e9
#define EPS 1e-4

typedef int type;

typedef pair<type, type> point;
const point infPoint(INF, INF);
typedef pair<type, type> vec;

#define x first
#define y second


point operator*(type alpha, point p){
	return point(alpha*p.x, alpha*p.y);
}

point operator+(point l, point r){
	return point(l.x + r.x, l.y + r.y);
}

vec operator-(point l, point r){ //might be confusing
	return vec(l.x - r.x, l.y - r.y);
}

type dot(vec p, vec q){
	return p.x*q.x + p.y*q.y;
}

double length(vec v){
	return hypot(v.x, v.y);
}

type cross(vec p, vec q){
	return p.x*q.y - p.y*q.x;
}

type operator*(vec p, vec q){
	return dot(p, q);
}

type operator^(vec p, vec q){
	return cross(p, q);
}

double operator~(vec v){
	return length(v);
}

void convex_hull(vector<point> &v, vector<point> &ans){
	if (v.size() < 3){
		ans = v;
		if (ans.front() != ans.back()) ans.push_back(ans.front());
		return;
	}
	sort(v.begin(), v.end());
	static vector<point> cap;
	cap.resize(0);
	cap.push_back(v[0]), cap.push_back(v[1]);
	for (int i = 2; i < v.size(); i++){
		while(cap.size() >= 2){
			int n = cap.size();
			if (((v[i] - cap[n-2])^(cap[n-1] - cap[n-2])) < 0) // <= exclude colinear points
				cap.pop_back();
			else
				break;
		}
		cap.push_back(v[i]);
	}
	static vector<point> cup;
	cup.resize(0);
	cup.push_back(v[0]), cup.push_back(v[1]);
	for (int i = 2; i < v.size(); i++){
		while(cup.size() >= 2){
			int n = cup.size();
			if (((v[i] - cup[n-2])^(cup[n-1] - cup[n-2])) > 0) //>= exclude colinear points
				cup.pop_back();
			else
				break;
		}
		cup.push_back(v[i]);
	}
	ans.resize(0);
	for (int i = 0; i < cap.size(); i++)
		ans.push_back(cap[i]);
	for (int i = cup.size() - 2; i >= 0; i--)
		ans.push_back(cup[i]);

}

int main(){ _
	int n;
	vector<point> v;
	vector<point> ch;
	while (true){
		cin >> n;
		if (n == 0) break;
		v.resize(n);
		for (int i = 0; i < n; i++)
			cin >> v[i].x >> v[i].y;
		int count = 0;
		while (v.size() > 0){
			convex_hull(v, ch);
			set<point> tmp(v.begin(), v.end());
			for (point p : ch)
				if (tmp.count(p)) tmp.erase(p);
			v = vector<point>(tmp.begin(), tmp.end());
			bool colinear = true;
			int sz = ch.size();
			for (int i = 2; i < sz; i++){
				colinear &= 
					((ch[i] - ch[i-1])^(ch[i-1] - ch[i-2])) == 0;
			}
			if (colinear)
				break;				
			count++;
		}
		if (count % 2 == 0)
			cout << "Do not take this onion to the lab!" << endl;
		else
			cout << "Take this onion to the lab!" << endl;
	}
	return 0;
}