- Practice
- Functional Programming
- Recursion
- Fibonacci Numbers

# Fibonacci Numbers

# Fibonacci Numbers

**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.