"""
Consider integer numbers from 0 to n - 1 
written down along the circle in such a way that 
the distance between any two neighboring numbers is equal 
(note that 0 and n - 1 are neighboring, too).

Given n and firstNumber, 
find the number which is written in the radially opposite position to firstNumber.
"""

def circleOfNumbers(n, firstNumber):
    return (firstNumber+(n/2))%n
