Circumradius of a Cyclic Quadrilateral using the length of Sides

Given integers A, B, C, and D denoting the length of sides of a Cyclic Quadrilateral, the task is to find the circumradius i.e., the radius of circumcircle of the given cyclic quadrilateral.

Examples:

Input: A = 3, B = 4, C = 5, D= 6
Output: 3.29

Input: A = 10, B = 30, C = 50, D = 20
Output: 27.78