A circle Circle(x, y, r) is defined by a center (x, y) and a radius r. It consists of all points (a, b) such that:
(a - x)^2 + (b - y)^2 <= r^2
Given integers (x, y, r), find the number of points (a, b) with
• [input] integer r
The radius of the circle.
Guaranteed constraint: 0 < r ≤ 104
• [output] integer |