#include <bits/stdc++.h> using namespace std; int i,j,k; double r,xx,yy,eps=1e-9; vector<double> x,y; bool was; double sqr(double x) { return x*x; } void check() { if (sqr(xx)+sqr(yy)>sqr(r-1)+eps) return; for (k=0; k<x.size(); k++) if (sqr(xx-x[k])+sqr(yy-y[k])<sqr(2)-eps) break; if (k<x.size()) return; printf("%.8f %.8f\n",xx,yy); x.push_back(xx); y.push_back(yy); was=true; } int main() { scanf("%lf",&r); while (true) { was=false; for (i=0; i<x.size() && !was; i++) for (j=0; j<i && !was; j++) { xx=0.5*(x[i]+x[j]); yy=0.5*(y[i]+y[j]); check(); } for (xx=-r; xx<=r && !was; xx++) for (yy=-r; yy<=r && !was; yy++) check(); if (!was) return 0; fflush(stdout); scanf("%lf%lf",&xx,&yy); x.push_back(xx); y.push_back(yy); } return 0; }