#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#undef _P
#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
//-------------------------------------------------------

int N,A,B;

double getrandom() {
	return rand()%10000/100000000.0;
}

vector<double> hoge(int n,int p) {
	vector<double> T;
	T.push_back(0);
	while(T.size()<n) T.push_back(T.back()+getrandom());
	if(n<2) return T;
	double L=0,R=17.3/(n-1);
	int i,x,y;
	FOR(i,100) {
		double M=(L+R)/2.0;
		int num=0;
		FOR(y,n) FOR(x,y) if((T[y]+y*M)-(T[x]+x*M)<=10) num++;
		if(num>=p) L=M;
		else R=M;
	}
	
	FOR(i,n) T[i]+=L*i;
	return T;
}

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	srand(time(NULL));
	cin>>N>>A>>B;
	B-=A;
	int U,V;
	for(U=1;U<=N;U++) {
		V=N-U;
		if(U>=V && U*(U-1)/2+V*(V-1)/2>=A) break;
	}
	
	x=A*1.0*U*(U-1)/(U*(U-1)+V*(V-1))+0.5;
	y=A-x;
	
	vector<double> S=hoge(U,x);
	vector<double> T=hoge(V,y);
	vector<double> C;
	FORR(s,S) FORR(t,T) {
		C.push_back(sqrt(400-(t-s)*(t-s)));
	}
	sort(ALL(C));
	
	FORR(s,S) _P("%.12lf %.12lf\n",s,C[B-1]);
	FORR(t,T) _P("%.12lf %.12lf\n",t,0);
	
	
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}