#include <bits/stdc++.h>
using namespace std;

typedef long double db;
const db eps=1e-8;
int sign(db k){
	if (k>eps) return 1;
	else if (k<-eps) return -1;
	return 0;
}
int cmp(db k1,db k2){return sign(k1-k2);}
int inmid(db k1,db k2,db k3){return sign(k1-k3)*sign(k2-k3)<=0;}

struct point{
	db x,y;
	point operator + (const point &k1){return (point){x+k1.x,y+k1.y};}
	point operator - (const point &k1){return (point){x-k1.x,y-k1.y};}
	point operator * (db k1){return (point){x*k1,y*k1};}
	point operator / (db k1){return (point){x/k1,y/k1};}
	db abs(){return hypot(x,y);}
	db abs2(){return x*x+y*y;}
	db dis(point k){return ((*this)-k).abs();}
	db dis2(point k){return ((*this)-k).abs2();}
	point unit(){
		db w=abs();
		return (point){x/w,y/w};
	}
	point turn90(){
		return (point){-y,x};	
	}
	int getP() const{
		return sign(y)==-1 || (sign(y)==0 && sign(x)==-1);	
	}
	void print(){
		cerr << "(" << x << "," << y << ") ";	
	}
};
db cross(point k1,point k2){return k1.x*k2.y-k1.y*k2.x;}
db dot(point k1,point k2){return k1.x*k2.x+k1.y*k2.y;}
int compareangle(point k1,point k2){
	return k1.getP()<k2.getP() || (k1.getP()==k2.getP() && sign(cross(k1,k2))>0);	
}
int checkLL(point k1,point k2,point k3,point k4){
	return cmp(cross(k3-k1,k4-k1),cross(k3-k2,k4-k2))!=0;	
}
point getLL(point k1,point k2,point k3,point k4){
	db w1=cross(k1-k3,k4-k3);
	db w2=cross(k4-k3,k2-k3);
	return (k1*w2+k2*w1)/(w1+w2);
}
struct line{
	point p[2];
	line(point k1,point k2){p[0]=k1;p[1]=k2;}
	point& operator [] (int k){return p[k];}
	int include(point k){return sign(cross(p[1]-p[0],k-p[0]))>0;}
	point dir(){return p[1]-p[0];}
	/*
	line push(){
		const db eps=1e-6;
		point delta=(p[1]-p[0]).turn90().unit()*eps;
		return {p[0]-delta,p[1]-delta};
	}
	*/
	void print(){
		p[0].print();
		p[1].print();	
	}
};
point getLL(line k1,line k2){return getLL(k1[0],k1[1],k2[0],k2[1]);}
int parallel(line k1,line k2){return sign(cross(k1.dir(),k2.dir()))==0;}
int sameDir(line k1,line k2){return parallel(k1,k2) && sign(dot(k1.dir(),k2.dir()))==1;}
int operator < (line k1,line k2){
	if (sameDir(k1,k2)) return k2.include(k1[0]);
	return compareangle(k1.dir(),k2.dir());	
}
int checkpos(line k1,line k2,line k3){return k3.include(getLL(k1,k2));}
vector<line> getHL(vector<line> &L){
	sort(L.begin(),L.end());
	/*
	cerr << "----" << endl;
	for (int i=0;i<(int)L.size();i++){
		L[i].print();
		cerr << endl;	
	}
	*/
	deque<line> q;
	for (int i=0;i<(int)L.size();i++){
		if (i && sameDir(L[i],L[i-1])) continue;
		while (q.size()>1 && !checkpos(q[q.size()-2],q[q.size()-1],L[i])) q.pop_back();
		while (q.size()>1 && !checkpos(q[1],q[0],L[i])) q.pop_front();
		q.push_back(L[i]);
	}
	while (q.size()>2 && !checkpos(q[q.size()-2],q[q.size()-1],q[0])) q.pop_back();
	while (q.size()>2 && !checkpos(q[1],q[0],q[q.size()-1])) q.pop_front();
	vector<line> ans;
	for (int i=0;i<(int)q.size();i++) ans.push_back(q[i]);
	return ans;
}

db w,h;
int n;
point a[1050];
db r[1050];

int main(){
	ios_base::sync_with_stdio(false);
	
	cout << fixed << setprecision(12);
	
	cin >> w >> h >> n;
	
	point C1=(point){0.0,0.0};
	point C2=(point){w,0.0};
	point C3=(point){w,h};
	point C4=(point){0.0,h};
	
	for (int i=1;i<=n;i++){
		cin >> a[i].x >> a[i].y >> r[i];	
	}
	for (int i=1;i<=n;i++){
	//	cerr << "-------------" << endl;
	//	cerr << "i : " << i << endl;
		vector<line> L;
		L.emplace_back(C1,C2);
		L.emplace_back(C2,C3);
		L.emplace_back(C3,C4);
		L.emplace_back(C4,C1);
		for (int j=1;j<=n;j++){
			if (i==j) continue;
			db d2=a[i].dis2(a[j]);
			point P=a[i]+(a[j]-a[i])*((r[i]*r[i]-r[j]*r[j]+d2)/2/d2);
			point Q=P+(a[j]-a[i]).turn90();
			L.emplace_back(P,Q);
		}
		/*
		cerr << "---" << endl;
		for (int i=0;i<(int)L.size();i++){
			L[i].print();
			cerr << endl;	
		}
		*/
		L=getHL(L);
		/*
		cerr << "-----" << endl;
		for (int i=0;i<(int)L.size();i++){
			L[i].print();
			cerr << endl;	
		}
		*/
		int sz=L.size();
		cout << sz << "\n";
		for (int j=0;j<sz;j++){
			point P=getLL(L[j],L[(j+1)%sz]);
			cout << P.x << " " << P.y << "\n";
		}
	}
	return 0;
}