#include <iostream>

#include <cstdio>

#include <cstring>

#include <algorithm>

#include <cmath>

using namespace std;

const int MAXN=100;

int n,l;

int st[MAXN],stop,cnt;

int ans[MAXN];

struct point{

	int x,y;

}p[MAXN];

bool cmp(point A,point B){

	if(A.y<B.y) return true;

	else if(A.y==B.y){

		if(A.x<B.x) return true;

	}

	return false;

}

bool multi(point a,point b,point c){

	return (a.x-c.x)*(b.y-c.y)-(a.y-c.y)*(b.x-c.x)<=0;

}

void slove(){

	stop=0; cnt=0;

	st[stop++]=0; st[stop++]=1;

	for(int i=2;i<n;i++){

		while(stop>1&&multi(p[st[stop-1]],p[i],p[st[stop-2]])) stop--;

		st[stop++]=i;

	}

	for(int i=0;i<stop;i++){

		ans[cnt++]=st[i];

	}

	stop=0;

	st[stop++]=n-1; st[stop++]=n-2;

	for(int i=n-3;i>=0;i--){

		while(stop>1&&multi(p[st[stop-1]],p[i],p[st[stop-2]])) stop--;

		st[stop++]=i;

	}

	for(int i=1;i<stop-1;i++)

	ans[cnt++]=st[i];

}

int main(){

	n=0;

	while(scanf("%d%d",&p[n].x,&p[n].y)!=EOF) n++;

	sort(p,p+n,cmp);

	slove();

	int i,k;

	for(k=0;k<cnt;k++){

		if(p[ans[k]].x==0&&p[ans[k]].y==0) break;

	}

	printf("(%d,%d)\n",p[ans[k]].x,p[ans[k]].y);

	for(int i=k+1;i<cnt;i++){

		printf("(%d,%d)\n",p[ans[i]].x,p[ans[i]].y);

	}

	for(int i=0;i<k;i++){

		printf("(%d,%d)\n",p[ans[i]].x,p[ans[i]].y);

	}

	return 0;

}