Objective
In this challenge, we learn about using the Fibonacci Function.

Resources
Here's a helpful video on the topic:

The Fibonacci Series

The Fibonacci sequence begins with and . These are the first and second terms, respectively. After this, every element is the sum of the preceding elements:

Fibonacci(n) = Fibonacci(n-1) + Fibonacci(n-2)  

Task
Given the starter code, complete the Fibonacci function to return the term.

We start counting from Fibonacci. This might differ from some other notations that treats Fibonacci.

The overall equation is:

             = 0 , n = 1
Fibonacci(n) = 1 , n = 2
               Fibonacci(n-1) + Fibonacci(n-2)  , n > 2

Input Format

One line of input, the integer .

Constraints

Output Format

Output one integer, the Fibonacci number.

Sample Input

3  

Sample Output

1  

Function Prototype
The starter code is provided for Scala. The code for accepting the input and displaying the output is provided. You will be provided the input parameter , and you need to return the Fibonacci term.

Sample Input and Output Values for the Fibonacci Series

fibonacci(3) = (0+1) = 1  
fibonacci(4) = (1+1) = 2  
fibonacci(5) = (1+2) = 3  

Requirements
Simple test cases can be cleared with a purely recursive function exponentially. To clear the more challenging test cases without violating the principles of functional programming, you might benefit from learning about the accumulator technique.