/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		System.out.println(getArea(0,1,10));
		System.out.println(getArea(1,1,10));
		System.out.println(getArea(1,0,10));
		System.out.println(getArea(1,-1,10));
		System.out.println(getArea(0,-1,10));
		System.out.println(getArea(-1,-1,10));
		System.out.println(getArea(-1,0,10));
		System.out.println(getArea(-1,1,10));
	}
	static int getArea(double xcoord, double ycoord , double radius) {
		if(xcoord*xcoord + ycoord*ycoord > radius*radius)
			return -1;
		double angle=Math.PI/2-Math.atan2(ycoord, xcoord);
		if(angle < 0)
			angle = 2*Math.PI+angle;
		int segments = 12;
		double angle_one_segment=2*Math.PI/segments;
		return 1 + (int)(angle/angle_one_segment);
	}
}