> #include <iostream>
> #include <fstream>
> using namespace std;
> 
> struct point{
> 	double x,y;
> 	char xstr[50],ystr[50];
> 	void print(){
> 		cout<<"("<<xstr<<","<<ystr<<")";
> 	}
> } p[10010];
> int pn;
> 
> void swap(point &a,point &b){
> 	point tmp=a;
> 	a=b;
> 	b=tmp;
> }
> 
> double xmult(point p1,point p2,point p0){
> 	return ( (p1.x-p0.x)*(p2.y-p0.y)-(p2.x-p0.x)*(p1.y-p0.y) );
> }
> double delt(double x1,double y1,double x2,double y2){
> 	return (x1*y2-x2*y1);
> }
> 
> int cmp(const void *a1,const void *a2){
> 	point p1=*(point *)a1;point p2=*(point *)a2;
> 	double tmp=xmult(p1,p2,p[0]);
> 	if(tmp==0){
> 		return (p2.x*p2.x+p2.y*p2.y-p1.x*p1.x-p1.y*p1.y);
> 	}
> 	return tmp;
> }
> 
> 
> 
> void init(){
> 	int root=0,i,j,k;
> 	for(i=1;i<pn;i++){
> 		if(p[i].y<p[root].y||p[i].y==p[root].y&&p[i].x<p[root].x){
> 			root=i;
> 		}
> 	}
> 	swap(p[0],p[root]);
> 	qsort(&p[1],pn-1,sizeof(p[1]),cmp);
> 
> 	int tmp=2;
> 	for(i=2;i<pn;i++){
> 		if(xmult(p[i],p[i-1],p[0])!=0){
> 			p[tmp++]=p[i];
> 		}
> 	}
> 	pn=tmp;
> 
> }
> 
> void convex(){
> 
> 	int stack[1000];
> 	int sn=0,i,j,k;
> /*	for(i=0;i<pn;i++){
> 		cout<<p[i].x<<" "<<p[i].y<<endl;
> 	}
> 	cout<<endl;*/
> 	stack[sn++]=0;
> 	stack[sn++]=1;
> 	stack[sn++]=2;
> 	for(i=3;i<pn;i++){
> 		int a=stack[sn-1],b=stack[sn-2];
> 		while(xmult(p[i],p[a],p[b])<=0){
> 			sn--;
> 			a=stack[sn-1];b=stack[sn-2];
> 		}
> 		stack[sn++]=i;
> 	}
> 	p[stack[0]].print();
> 	for(i=sn-1;i>=0;i--){
> 		cout<<" ";
> 		p[stack[i]].print();
> 	}
> 	cout<<endl;
> 
> }
> 
> 
> 
> void main(){
> //	ifstream cin("data.txt");
> 	while(1){
> 		char str[1000];
> 		cin.getline(str,1000);
> 		if(str[0]=='\0')break;
> 		int len=strlen(str);
> 		int i,curn=0;
> 		pn=0;
> 
> 		char curarr[100];
> 		double ln,rn;
> 		bool turnl=false;bool turnr=false;
> 		for(i=0;i<len;i++){
> 			if(!turnl&&!turnr){
> 				if(str[i]=='('){
> 					turnl=true;
> 				}else{
> 					continue;
> 				}
> 			}else if(turnl){
> 				if(str[i]==','){
> 					curarr[curn]='\0';
> 					turnl=false;
> 					turnr=true;
> 					ln=atof(curarr);
> 					p[pn].x=ln;
> 					strcpy(p[pn].xstr,curarr);
> 			
> 					curarr[0]='\0';
> 					curn=0;
> 				}else{
> 					curarr[curn++]=str[i];
> 				}
> 			}else if(turnr){
> 				if(str[i]==')'){
> 					curarr[curn]='\0';
> 					turnr=false;		
> 					turnl=false;
> 					rn=atof(curarr);
> 					p[pn].y=rn;
> 					strcpy(p[pn].ystr,curarr);
> 
> 					pn++;
> 					curarr[0]='\0';
> 					curn=0;
> 				}else{
> 					curarr[curn++]=str[i];
> 				}
> 			}
> 		}
> 		init();
> 		if(pn>=3){
> 			convex();
> 		}else{
> 			p[0].print();cout<<" ";p[1].print();cout<<" ";p[0].print();cout<<endl;
> 		}
> 	/*	for(i=0;i<pn;i++){
> 			cout<<p[i].x<<" "<<p[i].y<<endl;
> 		}*/
> 	}
> 
> }