in C++

Write a program that will trace how Fibonacci numbers are generated recursively (for any N) and display the trace in the following way : Example (N=4): Entering level 0 Entering level 2 Entering level 4 Exiting level 4 Entering level 3 Exiting level 3 Exiting level 2 Entering level 1 Entering level 3 Exiting level 3 Entering level 2 Entering level 4 Exiting level 4 Entering level 3 Exiting level 3 Exiting level 2 Exiting level 1 Exiting level 0

hint - the key here is to figure out how to do the indentation (hint - an additional variable that you pass in the recursive call that signifies the depth of recursion - and then use it in output statement for formatting)