Who is our Boss? LCA for n-array Tree

In a company which has CEO Bill and a hierarchy of employees. Employees can have a list of other employees reporting to them, which can themselves have reports, and so on. An employee with at least one report is called a manager.
Please implement the closestCommonManager method to find the closest manager (i.e. farthest from the CEO) to two employees. You may assume that all employees eventually report up to the CEO. Assume the following class which you can’t change –