Recursion: Fibonacci Numbers (Swift 3)

Fibonacci.txt

import Foundation

func fibonacci (n: Int) -> Int {
    // Write your code here.
    if (n == 0 || n == 1) {
        return 1;
    }
    
    return fibonacci(n: n-1) + fibonacci(n: n-2)
}

// read the integer n
let n = Int(readLine()!)!

// print the nth fibonacci number
print(fibonacci(n: n-1))