#!/usr/bin/python
import os,sys,math

def FindYonCircle(x,x0,y0,r):
    # (x - x0)**2 + (y - y0)**2 = r**2
    if x - x0 > r or x0 - x > r:
        return 0
    else:
        y1 = (r**2-(x-x0)**2)**0.5 + y0
        y2 = - (r**2-(x-x0)**2)**0.5 + y0
        return y1,y2

x0,y0 = 0,0
r = 1.5
x = -2
xmax = 2
dx = 0.01
while x <= xmax:
    if FindYonCircle(x,x0,y0,r) == 0:
        x = x + dx
        continue
    y1,y2 = FindYonCircle(x,x0,y0,r)
    print x,y1
    print x,y2
    x = x + dx