#include "iostream"
#include "math.h"
using namespace std;




void main()
{
	for(float j=19.75,x=0,y=0;y<=j;x+=0.25,y+=0.25)
	{
		if(x>=4)
		{x-=4;cout<<'\n';}
		if(x>=0&&x<=2)
			cout<<"\nx="<<y<<";y="<<sqrt(4-(x-2)*(x-2));
		else
			cout<<"\nx="<<y<<";y="<<-sqrt(4-(x-2)*(x-2));
	}
}