#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<iomanip>
#include<math.h>
#include<complex>
#include<queue>
#include<deque>
#include<stack>
#include<map>
#include<set>
#include<bitset>
#include<functional>
#include<assert.h>
#include<numeric>
using namespace std;
#define REP(i,m,n) for(int i=(int)(m) ; i < (int) (n) ; ++i )
#define rep(i,n) REP(i,0,n)
using ll = long long;
const int inf=1e9+7;
const ll longinf=1LL<<60 ;
const ll mod=1e9+7 ;


struct Xor128{
    unsigned x,y,z,w;

    Xor128(unsigned w_=88675123):x(123456789),y(362436069),z(521288629),w(w_){};

    inline unsigned xor128(){
        unsigned t;
        t = x^(x<<11);
        x = y;
        y = z;
        z = w;
        return w = (w^(w>>19))^(t^(t>>8));
    }

    int nextInt(int x,int y){
        if(x>y)swap(x,y);
        return xor128()%(y-x)+x;
    }

    double nextDouble(double a,double b){
        return (double)(xor128()&0xffff)/0xffff*(b-a)+a;
    }

};
int main(){
    cout<<fixed<<setprecision(10);
    int n,a,b;
    cin>>n>>a>>b;
    auto rnd = Xor128();
    REP(i,1,n){
        int x = i, y = n-i;
        int B = x*(x-1)/2+y*(y-1)/2;
        if(B>b)continue;
        double l1 = 0, l2 = 0, r1=1, r2=1;
        vector<double> rx(2), ry(2);
        rx[1]=ry[1]=19.95;
        rep(i,x-2)rx.push_back(rnd.nextDouble(0,19.95));
        rep(i,y-2)ry.push_back(rnd.nextDouble(0,19.95));
        sort(rx.begin(),rx.end());
        sort(ry.begin(),ry.end());
        rep(_,25){
            double m1 = (l1+r1)/2, m2 = (l2+r2)/2;
            vector<double> xs(x), ys(y);
            rep(i,x)xs[i]=m1*rx[i];
            rep(i,y)ys[i]=m2*ry[i];
            int s =x*(x-1)/2+y*(y-1)/2;
            rep(i,x){
                s -= xs.end()-upper_bound(xs.begin(),xs.end(),xs[i]+10);
            }
            rep(i,y){
                s -= ys.end()-upper_bound(ys.begin(),ys.end(),ys[i]+10);
            }
            if(s==a)break;
            if(s<a)r1=m1, r2=m2;
            else l1=m1, l2=m2;
        }
        double m1 = (l1+r1)/2, m2 = (l2+r2)/2;
        vector<double> xs(x), ys(y);
        rep(i,x)xs[i]=m1*rx[i];
        rep(i,y)ys[i]=m2*ry[i];
        int s = x*(x-1)/2+y*(y-1)/2;
        rep(i,x){
            s -= xs.end()-upper_bound(xs.begin(),xs.end(),xs[i]+10);
        }
        rep(i,y){
            s -= ys.end()-upper_bound(ys.begin(),ys.end(),ys[i]+10);
        }
        if(s!=a)continue;
        double l = 0, r = 40;
        double h = 10.1;
        rep(_,30){
            double m = (l+r)/2;
            int cnt = 0;
            rep(i,x)rep(j,y){
                if(h*h+(xs[i]-ys[j]-m)*(xs[i]-ys[j]-m)<=400)++cnt;
            }
            if(B+cnt==b){
                vector<double> X, Y;
                rep(i,x)X.push_back(0),Y.push_back(xs[i]);
                rep(i,y)X.push_back(h),Y.push_back(ys[i]+m);
                int cntA = 0, cntB = 0;
                rep(i,n)rep(j,i){
                    if((X[i]-X[j])*(X[i]-X[j])+(Y[i]-Y[j])*(Y[i]-Y[j])<=100)++cntA;
                    if((X[i]-X[j])*(X[i]-X[j])+(Y[i]-Y[j])*(Y[i]-Y[j])<=400)++cntB;
                }
                if(cntA==a&&cntB==b){
                    rep(i,x)cout<<0<<" "<<xs[i]<<endl;
                    rep(i,y)cout<<h<<" "<<ys[i]+m<<endl;
                    return 0;
                }
            }
            if(B+cnt>b)l=m;
            else r=m;
        }

    }

    return 0;
}