This exercise covers the implementation of a class Timer.

$(1)$ It contains three private integer member variables, hours, minutes, and seconds.

$(2)$ It contains two constructors.

default constructor that sets the hours to be $0,$ minutes to be $1,$ and seconds to be $0$

an overloaded constructor that takes three integers as input to set the hours, minutes, and seconds of the object

$(3)$ It contains the following functions in the public section of the class

void setHours$($int$)$; $--$ sets the hours with the input value

void setMinutes$($int$)$; $--$ set the minutes with the input value

void setSeconds$($int$)$; $--$ set the seconds with the input value

void start$()$; $--$ starts the count down of the timer by reducing the value of seconds by $1$ every second

string toString$()$; $--$ output the current time in a specific format

$(4)$ It contains three private $($or helper$)$ functions that update the current seconds, minutes, and hours to get the correct time

void reduceSeconds$()--$ reduce the current value of seconds by $1$ if it is larger than $0,$ otherwise$/$else$,$ call the reduceMinutes$()$ function and set the current value of seconds to be $59$

void reduceMinutes$()--$ reduce the current value of minutes by $1$ if it is larger than $0,$ otherwise$/$else$,$ call the reduceHours$()$ function and set the current value of minutes to be $59$

void reduceHours$()--$ reduce the current value of hours by $`$

Note: You should declare the Timer class with the above members in the "timer.h$"$ file, and provide the implementation of the respective member functions in the "timer.cpp$"$ file. The implementations of the start$()$ and toString$()$ functions are provided to you in the "timer.cpp$"$ function. Also, the main$()$ function is provided to you so that you do not need to implement it$.$

You are encouraged to use your local IDE to complete this exercise, and modify the main function to enable a timer with different time period than $5$ seconds.