checking never ends.
no problems with small inputs. but it takes almost infinite time with large numbers, bigger than 100.
I believe I am trying quite ordinary soluution. Its basically equals to this code
def fib(n): if n==0 : return 0 if n==1 : return 1 return fib(n-1) + fib(n-2)
Is this normal so I should wait more, or do I have to find better algorithm?