Determine at how many points two circles intersect.
6 numbers x1, y1, r1, x2, y2, r2, where x1, y1, x2, y2 are the coordinates of the centers of the circles, r1, r2 are their radii.
All numbers are real, do not exceed 1000000000 modulo, and are specified with no more than 3 decimal places.
Output a single number, the number of intersection points. If the number of points is infinite, output −1.