Develop an object-oriented programming (OOP) application to create two clocks that display simultaneously and allow for user input using secure and efficient C++ code. 1. Clock12: Time should be displayed in 12-hour format where the clock does not exceed 12:59:59.

2. Clock24: Time should be displayed in 24-hour format where the clock does not exceed 23:59:59.

3. Both clocks should display on the screen with the current time in the proper format.

Any clue where to even start?