Why this program is taking too much time?
It's not even showing compile error!!!!!
It is just really inefficient because you are recursing so many times for such a big number, the recursion ends up stacking like 2^98 times(I'm not sure about the exact value it's probably a lot less but that's just a guess). If you want to have a method to get Fibonacci for big numbers, I recommend you don't use recursion, because it calls the function so many times, especially for larger numbers.