I'll just write fib. short for fibonacci fibonacci of 2 plus fibbonacci of (3-2) plus fibonacci of 1 so it reduces to that or breaks down to that and over here fibonacci of 2 2 is not less than 2, so we are going to have to return fibonacci of 2 -1 fibonacci of 1 plus fibonacci of 2-2 so plus fibonacci of 0 so it breaks down to those two calls to fibonacci and over here fibonacci(2) same thing. we made a call to fibonacci(2) that's going to break down just like that fibonacci(2) did it will break down to a call to of fibbonacci of 1 and fibonacci(0) and then we have fibonacci of 1 so this is interesting.